Wireless alarm system

• US 5,987,058 A
• Filed: 06/07/1995
• Issued: 11/16/1999
• Est. Priority Date: 11/02/1988
• Status: Expired due to Fees

• Current Assignee: NorthPeak Wireless, LLC, M&FC Holding, LLC (Xylem, Inc.)
• Original Assignee: Axonn LLC (Globalstar Incorporated)
• Inventors: Arthur, James D., Rouquette, Robert E., Sanderford, H. Britton
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US08/487,523
• Time in Patent Office: 1,623 Days
• Field of Search: 375/200, 375/202, 375/208, 375/210, 375/367, 455/100, 455/113, 370/515
• US Class Current: 375/141
• CPC Class Codes: G08B 25/10 using wireless transmission systems G08B25/009 takes precedence
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/70756 Jumping within the code, i.e. masking or slewing H04B1/70758 takes precedence
• CPC Class Codes: H04B 1/70757 with increased resolution, i.e. higher than half a chip H04B1/70758 takes precedence
• CPC Class Codes: H04B 1/7077 Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
• CPC Class Codes: H04B 1/708 Parallel implementation
• CPC Class Codes: H04B 2201/70715 with application-specific features

Abstract

A wireless alarm system using spread spectrum transmitters, fast frequency shift keying, spread spectrum receivers and computer with a display. The spread spectrum transmitter includes an oscillator coupled to a microprocessor with chip code generation means, preamble register, address register and data register. The spread spectrum receiver acquires synchronization of the spread spectrum signal using a microprocessor coupled to the quieting, signal strength or baseband output of the receiver, with a two step algorithm. The steps comprise achieving a coarse lock and a fine lock to the spread spectrum signal.

Claims

1. In a method for controlling a spread spectrum transmitter having an oscillator provided with a modulation input, the improvement comprising the steps of:

maintaining the transmitter in a low current state between transmissions of spread spectrum signals;

generating one or more chip code sequence repetitions during a transmitting interval when the transmitter is not maintained in the low current state;

inputting said one or more chip code sequence repetitions as a modulating voltage to the modulation input of the oscillator thereby causing a frequency deviation in a transmitted signal to be output from the transmitter; and

applying additionally a device address and data to the modulation input of the oscillator after inputting the one or more chip code sequence repetitions for a predetermined time period so as to allow an associated receiver to achieve initial spread spectrum timing synchronization.

2. The method of claim 1, further comprising the step of:

applying a limited number of address and data bits to the modulation input of the oscillator so that the associated receiver, having a synchronization device therein, is able to receive the transmitted signal and decode the data in said transmitted signal after completion of a coarse search and without said synchronization device performing continuous chip code synchronization on said transmitted signal.

3. The method of claim 1, further comprising:

applying the one or more chip code sequence repetitions as the modulating voltage to said modulation input of said oscillator at a chip rate of approximately 1.0 MHZ to 1.3 MHZ so as to produce a frequency shift keying (FSK) spread spectrum modulated signal.

4. The method of claim 3, wherein the oscillator is modulated with fast frequency shift key (FFSK) modulation.

5. The method of claim 1, wherein said applying step comprises:

applying the one or more chip code sequence repetitions to the modulation input of a phase shift keying (PSK) modulator that is included in said oscillator at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a PSK spread spectrum modulated signal as said transmitted signal.

6. The method of claim 1, wherein at least one of the data applied to the modulation input causes a priority transmission at an increased rate of message transmission.

7. The method of claims 1 or 6, further comprising the steps of:

transmitting redundant supervisory messages by repetitively applying a supervisory message to said modulation input;

presetting a low power timer coupled to a wake up means with a pseudorandom number; and

initiating said transmissions from said transmitter by said wake up means.

8. The method of claim 1, further comprising the steps of:

providing message redundancy by generating plural transmit messages applied to said modulation input for transmission by the transmitter;

amplifying an oscillator signal output by said oscillator via a power amplifier; and

controlling respective active states of said oscillator and said power amplifier via a control means attached to an enable input of said oscillator and an enable input of said power amplifier,

said controlling step comprising,

reducing a power drain and ensuring adequate settling time by enabling said oscillator and said power amplifier in said respective active states only for a duration corresponding to when a transmission is made from the transmitter.

9. The method of claim 8, further comprising the step of:

providing a delay to allow a timing reference used by said generating step to settle prior to a transmission.

10. The method of claim 1, further comprising the steps of:

providing message redundancy comprising generating plural transmit messages applied to said modulation input for transmission by the transmitter;

detecting data errors in data to be transmitted using an error detection generation device; and

modulating the output frequency of the oscillator less broadly than when the one or more chip code sequence repetitions alone is applied to the modulation input of the oscillator comprising,

applying addresses stored in an address storage device configured to store addresses and error detection signals generated by the error detection generation device to the modulation input of the oscillator at an amplitude less than the amplitude of the one or more chip code sequence repetitions applied to the modulation of the input by the generating step.

11. The method of claim 1, further comprising the steps of:

providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter; and

setting a frequency deviation of the oscillator in response to modulating signals applied to the modulation input of the oscillator to generate a fast frequency shift keying signal with a spectrally efficient transmitted bandwidth.

12. A spread spectrum transmitter comprising:

oscillator means having a modulation input and producing at an output thereof a variable frequency output tuned to a carrier frequency to be transmitted;

a chip code generator which applies a chip code to the modulation input of the oscillator means to change the frequency output of the oscillator means to directly produce a spread spectrum frequency shift keying (FSK) modulated signal at said carrier frequency;

a power amplifier coupled to the output of the oscillator means and configured to produce an amplified spread spectrum FSK modulated signal at said carrier frequency;

a filter coupled to an output of the power amplifier and configured to produce a filtered amplified spread spectrum FSK modulated signal at said carrier frequency; and

an antenna coupled to an output of the filter and configured to transmit the filtered amplified spread spectrum FSK modulated signal at said carrier frequency.

13. The spread spectrum transmitter according to claim 12, further comprising:

a crystal oscillator configured to apply a clock signal to said chip code generator; and

means for locking the oscillator means to the clock signal produced by said crystal oscillator.

14. The spread spectrum transmitter according to claim 13, wherein:

said chip code generator being clocked at a chip rate of approximately 1.0 MHZ to 1.3 MHZ.

15. The spread spectrum transmitter according to claim 12, further comprising:

a data storage device coupled to the modulation input of the oscillator means and configured to apply data to said modulation input, said data having an amplitude such that a frequency change produced in the transmitter carrier frequency by the oscillator means as a result of said data being applied thereto is less spectrally broad than that of the frequency change produced in the transmitter carrier frequency when only a chip code from the chip code generator is applied to the modulation input of the oscillator means, thereby simultaneously producing FSK data modulation and FSK spreading modulation at a desired carrier frequency.

16. The spread spectrum transmitter according to claim 15, further comprising:

timer means for causing the chip code generator to produce one or more chip code sequences applied to the modulation input of the oscillator means for a predetermined time period, for the purpose of spread spectrum synchronization at a receiver, prior to the data storage device outputting sequential data bits to the modulation input of the oscillator means.

17. The spread spectrum transmitter according to claim 15, further comprising:

timer means for applying, for a predetermined time period, to the modulation input of the oscillator means, for enabling spread spectrum synchronization at a receiver, the chip code produced by said chip code generator, said chip code having one or more chip code sequences and an amplitude and pattern that enable a data detector in the receiver to be precharged in order to overcome system tolerances between said transmitter and the receiver;

wherein

said timer means being set to produce a predetermined delay in application of said data from the data storage device to the modulation input of the oscillator means after application of only said chip code.

18. The spread spectrum transmitter according to claims 12, 15, 16 or 17, further comprising:

frequency stabilization means for reducing a frequency offset error at the oscillator means.

19. The spread spectrum transmitter according to claims 12, 13, 14, 15, 16 or 17, wherein:

said oscillator means includes an enable input;

the power amplifier includes an enable input; and

said transmitter further comprises control means connected to the enable input of the oscillator means and the enable input of the power amplifier for enabling said oscillator means and said power amplifier only during transmission from the transmitter, thereby reducing a power drain and ensuring adequate oscillator settling time.

20. The spread spectrum transmitter according to claims 12, 15, 16 or 17, further comprising:

modulation index setting means for setting a frequency deviation of the oscillator means in response to modulating signals applied to the modulation input of the oscillator means to generate fast frequency shift keying (FFSK) transmissions.

21. The spread spectrum transmitter according to claim 20, further comprising:

a control means for providing a delay prior to enabling the input of the power amplifier, thereby allowing a timing reference of the chip code generator to settle prior to a transmission.

22. The spread spectrum transmitter according to claims 12, 15, 16 or 17, further comprising:

an address storage device configured to store addresses;

error detection generation means for detecting data errors in data to be transmitted; and

means for applying, simultaneous with said chip code, addresses stored in the address storage device and error detection signals generated by the error detection generation means to the modulation input of the oscillator means at an amplitude less than the amplitude of said chip code.

23. The spread spectrum transmitter according to claims 12 or 15, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, said data message input to said modulation input of said oscillator means and having a limited message length so that once initial spread spectrum synchronization is achieved by a receiver, the receiver can receive without performing continuous chip code resynchronization.

24. The spread spectrum transmitter according to claim 19, wherein:

said control means provides a delay prior to enabling the input of the power amplifier, thereby allowing a timing reference of the chip code generator to settle prior to a transmission.

25. The spread spectrum transmitter according to claims 16 or 17, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, said data message coupled to said modulation input of said oscillator means and having a limited message length so that once initial spread spectrum synchronization is achieved by the receiver, the receiver can receive without performing continuous chip code resynchronization.

26. The spread spectrum transmitter according to claim 12, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

an address storage device configured to store addresses;

error detection generation means for detecting data errors in data to be transmitted; and

means for modulating the output frequency of the oscillator means less broadly than when the chip code alone is applied to the modulation input of the oscillator means, by applying addresses stored in the address storage device and error detection signals generated by the error detection generation means to the modulation input of the oscillator means at an amplitude less than the amplitude of the chip code applied to the modulation of the input by the chip code generator.

27. The spread spectrum transmitter according to claim 12, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter; and

modulation index setting means for setting a frequency deviation of the oscillator means in response to modulating signals applied to the modulation input of the oscillator means to generate a fast frequency shift keying signal with a spectrally efficient transmitted bandwidth.

49. The spread spectrum transmitter according to claims 15, 28 or 44, further comprising:

initiating means for initiating repetitive application of a supervisory message to said modulation input thereby transmitting repetitive supervisory messages; and

a wake-up means coupled to a low power timer preset with a pseudorandom number for initiating transmission of data applied to said modulation input.

50. The spread spectrum transmitter according to claims 15, 28, 35 or 44, wherein at least one of the data applied to the modulation input causes a priority transmission at an increased rate of transmission.

51. The spread spectrum transmitter according to claim 50, further comprising:

initiating means for initiating repetitive application of a supervisory message to said modulation input thereby transmitting repetitive supervisory messages; and

a wake-up means coupled to a low power timer preset with a pseudorandom number for initiating said priority transmission by said transmitter.

59. The spread spectrum transmitter according to claims 12, 28, 52 or 53, further comprising:

means for generating plural transmit messages applied to said modulation input at different time positions with a very fine resolution for transmission with message redundancy.

60. The spread spectrum transmitter according to claim 59, wherein said means for generating plural transmit messages comprises:

means for generating said plural transmit messages with different time interval lengths therebetween, said different time positions providing message redundancy with a lowered probability of repeat collisions with transmissions from multiple co-channel transmitters, and for presetting a low power timer with a pseudorandom number; and

a wake-up means coupled to said low power timer for initiating said transmission of said plural transmit messages.

61. The spread spectrum transmitter according to claim 60, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, said data message input to said modulation input and having a limited message length so that once initial spread spectrum synchronization is achieved by a receiver that receives said data message, the receiver can receive without performing continuous chip code synchronization.

64. The spread spectrum transmitter according to claim 12, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

said oscillator means having an enable input;

said power amplifier having an enable input; and

control means connected to the enable input of said oscillator means and the enable input of said power amplifier for enabling respective active operational states of said oscillator means and said power amplifier only during a transmission from the transmitter, thereby reducing power drain and ensuring adequate settling time.

68. The spread spectrum transmitter according to claims 64, 65, 66 or 67, wherein:

said control means provides a delay prior to enabling said power amplifier, thereby allowing a timing reference of the chip code generator to settle prior to a transmission.

83. The spread spectrum transmitter according to claims 12, 35, 44, 52, 72 or 79, wherein the transmitter is configured to communicate with at least one receiver having a bandwidth limiting device coupled to a despreading device such that a received spread spectrum signal is bandlimited to approximately 2 MHZ prior to despreading.

28. A spread spectrum transmitter comprising:

a voltage controlled oscillator having a modulation input and a frequency output tuned to a predetermined carrier frequency;

a chip code generator coupled to the modulation input of the voltage controlled oscillator so as to apply a chip code sequence to the modulation input and modulate the frequency output of the voltage controlled oscillator to generate a spread spectrum signal; and

data storage means coupled to the modulation input of the voltage controlled oscillator for simultaneously applying data stored therein to the modulation input of the voltage controlled oscillator with said chip code sequence so as to produce a fast frequency shift keying signal;

wherein a modulation frequency deviation of said data is less spectrally broad than a modulation frequency deviation of said chip code sequence.

29. The spread spectrum transmitter according to claim 28, further comprising:

a power amplifier for amplifying the frequency output of the voltage controlled oscillator,

said voltage controlled oscillator and said power amplifier each having an enable input; and

control means connected to the respective enable inputs of the voltage controlled oscillator and the power amplifier for enabling said voltage controlled oscillator and said power amplifier only during transmission from the transmitter, thereby reducing power drain and ensuring adequate settling oscillator time.

30. The spread spectrum transmitter according to claim 28, further comprising:

an address storage device for storing addresses;

means for generating plural transmit messages and applying said plural transmit messages to said modulation input so as to provide message redundancy;

error detection generation means for detecting data errors in data to be transmitted; and

means for applying, simultaneous with said chip code sequence, the addresses stored in the address storage device and then for applying error detection signals generated by the error detection generation means to the modulation input of the voltage controlled oscillator at an amplitude less than the amplitude of the chip code sequence applied to the modulation input by the chip code generator.

31. The spread spectrum transmitter according to claim 28, further comprising:

frequency stabilization means for reducing offset error in the frequency output of the voltage controlled oscillator.

32. The spread spectrum transmitter according to claim 31, further comprising:

modulation index setting means for setting a frequency deviation of the voltage controlled oscillator in response to modulating signals applied to the modulation input of the voltage controlled oscillator to generate fast frequency shift keying (FFSK) in order to minimize transmitted band width.

33. The spread spectrum transmitter according to claim 32, further comprising:

an address storage device for storing addresses;

error detection generation means for detecting data errors in data to be transmitted; and

means for applying, simultaneous with said chip code sequence, addresses stored in the address storage device and then applying error detection signals generated by the error detection generation means to the modulation input of the voltage controlled oscillator at an amplitude less than the amplitude of said chip code sequence applied to the modulation input of the voltage controlled oscillator.

34. The spread spectrum transmitter according to claim 33, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, said data message is input to said modulation input of said voltage controlled oscillator and having a predetermined message length so that once initial spread spectrum synchronization is achieved by a receiver, the receiver can receive without performing continuous chip code resynchronization.

63. The spread spectrum transmitter according to claims 28, 52 or 53, further comprising:

means for generating plural transmit messages and applying said plural transmit messages to said modulation input so as to provide message redundancy; and

modulation index setting means for setting a frequency deviation of the voltage controlled oscillator in response to modulating signals applied to the modulation input of the voltage controlled oscillator so as to generate fast frequency shift keying (FFSK) and minimize transmitted bandwidth.

65. The spread spectrum transmitter according to claim 28, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

said voltage controlled oscillator having an enable input;

a power amplifier having an enable input and configured to amplify the output of said voltage controlled oscillator; and

control means connected to the enable input of said voltage controlled oscillator and the enable input of said power amplifier for enabling respective active operational states of said voltage controlled oscillator and said power amplifier only during a transmission from the transmitter, thereby reducing power drain and ensuring adequate settling time.

35. A spread spectrum transmitter comprising:

carrier generation means for generating a carrier at a carrier frequency;

a phase shift keying modulator having an input coupled to the output of the carrier generation means and having a modulation input;

a chip code generator connected to the modulation input of the phase shift keying modulator and configured to apply a chip code sequence to the modulation input of the phase shift keying modulator so as to produce a phase shift keying spread spectrum modulated signal at said carrier frequency at an output of said phase shift keying modulator;

a power amplifier having an input coupled to the output of the phase shift keying modulator;

a filter having an input coupled to an output of the power amplifier;

an antenna having an input coupled to an output of the filter to transmit an amplified and filtered phase shift keying spread spectrum modulated signal at said carrier frequency;

timer means for enabling application of multiple chip code sequences to the modulation input of the phase shift keying modulator prior to transmission of data so as to promote spread spectrum timing synchronization in a receiver that receives a spread spectrum modulated signal transmitted by the antenna;

address storage means for storing addresses;

data storing means for storing data; and

error detection generation means for providing a plurality of error detection bits to secure the data stored in said data storing means and addresses stored in said address storage means and said error detection bits to be transmitted with said data.

36. The spread spectrum transmitter according to claim 35, further comprising:

frequency stabilization means for reducing frequency offset error at the output of the carrier generation means.

37. The spread spectrum transmitter according to claim 36, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, coupled to said modulation input of said phase shift keying modulator, said data message having a predetermined message length so that once initial spread spectrum synchronization is achieved by the receiver, the receiver can receive without performing continuous chip code resynchronization.

38. The spread spectrum transmitter according to claim 35, wherein:

said carrier generation means and said power amplifier each having an enable input; and

control means connected to the enable input of the carrier generation means and the enable input of the power amplifier for enabling an operational state of said carrier generation means and said power amplifier during transmission from the transmitter, and for placing said carrier generation means and said power amplifier means in a low current state when not transmitting a message, thereby reducing a power drain and ensuring adequate settling time.

39. The spread spectrum transmitter according to claim 38, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, coupled to said modulation input of said phase shift keying modulator, said data message having a predetermined message length so that once initial spread spectrum synchronization is achieved by the receiver, the receiver can receive without performing continuous chip code resynchronization.

40. The spread spectrum transmitter according to claim 38, wherein:

said control means provides a delay prior to enabling the input of the power amplifier, thereby allowing a timing reference of the chip code generator to settle prior to a transmission.

41. The spread spectrum transmitter according to claim 35, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter; and

modulation index setting means for setting a frequency deviation of the carrier generation means in response to modulating signals applied to the modulation input of the carrier generation means to generate a fast frequency shift keying signal with a spectrally efficient transmitted bandwidth.

42. The spread spectrum transmitter according to claim 35, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

the error detection generation means for detecting data errors in data to be transmitted; and

means for modulating the output frequency of the carrier generation means less broadly than when the chip code sequence alone is applied to the modulation input of the carrier generation means, by applying at least one of the addresses stored in the address storage means and error detection signals generated by the error detection generation means to the modulation input of the carrier generation means at an amplitude less than the amplitude of the chip code sequence applied to the modulation of the input by the chip code generator.

43. The transmitter of claim 35, wherein:

said chip code generator generates the chip code sequence at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a phase shift keying spread spectrum modulated signal.

47. The transmitter of claims 35 or 44, wherein said means for generating plural transmit messages comprises:

means for generating said plural transmit messages with different time interval lengths therebetween, said different time positions providing message redundancy with a lowered probability of repeat collisions with transmissions from multiple co-channel transmitters, and for presetting a low power timer with a pseudorandom number; and

a wake-up means coupled to said low power timer for initiating said transmission of said plural transmit messages.

48. The spread spectrum transmitter according to claims 35 or 44, further comprising:

means for generating a data message at a data rate in excess of 14 kb/s and a chip rate less than 1.3 MHZ, said data message is input to said modulation input of said phase shift keying modulator and having a predetermined message length so that once initial spread spectrum synchronization is achieved by the receiver, the receiver can run open loop without performing continuous chip code resynchronization.

66. The spread spectrum transmitter according to claim 35, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

said carrier generation means having an enable input;

said power amplifier having an enable input;

control means connected to the enable input of said carrier generation means and the enable input of said power amplifier for enabling respective active operational states of said carrier generation means and said power amplifier only during a transmission from the transmitter, thereby reducing power drain and ensuring adequate settling time.

44. A spread spectrum transmitter comprising:

carrier frequency generation means for generating a carrier frequency at an output thereof;

frequency stabilization means for reducing frequency offset error at the output of the carrier frequency generation means;

a phase shift keying modulator having an input coupled to the output of the carrier frequency generation means and having a modulation input;

a chip code generator connected to the modulation input of the phase shift keying modulator and configured to apply a chip code sequence to the modulation input of the phase shift keying modulator and thereby to produce a phase shift keying spread spectrum modulated signal at the carrier frequency of the carrier frequency generation means at an output of said phase shift keying modulator;

a power amplifier having an input coupled to the output of the phase shift keying modulator;

a filter having an input coupled to an output of the power amplifier; and

an antenna having an input coupled to an output of the filter to transmit an amplified and filtered phase shift keying spread spectrum modulated signal at a desired transmitted frequency;

timer means for controlling application from said chip code generator of one or more chip code sequences to the modulation input of the phase shift keying modulator prior to transmission of data, thereby to promote spread spectrum synchronization in a receiver receiving a spread spectrum modulated signal transmitted by the antenna;

address storage means for storing addresses;

data means for storing data;

error detection generation means for providing a plurality of error detection bits to secure the data to be transmitted; and

application means for applying addresses stored in the address storage means, data stored in the data means, and error detection signals generated by the error detection generation means to the modulation input of the phase shift keying modulator, thereby sequentially outputting addresses, data and error detection signals.

45. The spread spectrum transmitter according to claim 44, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

said error detection generation means for detecting data errors in data to be transmitted; and

means for sequentially modulating the output frequency of the carrier frequency generation means less broadly than when the chip code sequence alone is applied to the modulation input of the carrier frequency generation means, by applying addresses stored in the address storage means and error detection signals generated by the error detection generation means to the modulation input of the carrier frequency generation means at an amplitude less than the amplitude of the chip code sequence applied to the modulation of the input by the chip code generator.

46. The spread spectrum transmitter according to claim 44, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter; and

modulation index setting means for setting a frequency deviation of the carrier generation means in response to modulating signals applied to the modulation input of the carrier generation means to generate a fast frequency shift keying signal with a spectrally efficient transmitted bandwidth.

67. The spread spectrum transmitter according to claim 44, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

said carrier frequency generation means having an enable input;

said power amplifier having an enable input;

control means connected to the enable input of said carrier frequency generation means and the enable input of said power amplifier for enabling respective active operational states of said carrier frequency generation means and said power amplifier only during a transmission from the transmitter thereby reducing power drain and ensuring adequate settling time.

52. A spread spectrum transmitter comprising:

oscillator means, including a voltage controlled oscillator having a modulation input, for generating an output signal at a carrier frequency;

processor means for controlling transmissions of said output signal from the voltage controlled oscillator, said processor means including processor oscillator means for producing a frequency stabilizing reference clock signal;

means for stabilizing the frequency of the voltage controlled oscillator by locking the frequency of the voltage controlled oscillator to the frequency stabilizing reference clock signal produced by said processor oscillator means;

timer means for defining an active operating state in which the processor means and the voltage controlled oscillator are enabled in an active state, said timer means first enabling said processor oscillator means to operate for a predetermined time to stabilize the frequency output of the processor oscillator means and thereafter enabling said voltage controlled oscillator to operate for the predetermined time to allow the frequency output of the voltage controlled oscillator to stabilize, said timer means also defining an inactive state in which the processor means is not enabled and the voltage controlled oscillator is not enabled and the output signal is not produced at the carrier frequency; and

said processor means further comprising chip code generator means clocked by the processor oscillator means for generating a chip code signal applied to the oscillator means, and thereby locking the carrier frequency to the chip code signal as a result of the voltage controlled oscillator and the chip code generator means sharing a common reference oscillator.

53. The spread spectrum transmitter according to claim 52, wherein said oscillator means comprises:

phase shift keying means connected to the output of the voltage controlled oscillator, thereby producing a spread spectrum phase shift keying signal at said carrier frequency.

54. A spread spectrum transmitter according to claims 52 or 53, further comprising:

an address storage device for storing addresses;

means for generating plural transmit messages and applying said plural transmit messages to said modulation input so as to provide message redundancy;

error detection generation means for detecting data errors in data to be transmitted; and

means for applying, simultaneous with said chip code signal, the addresses stored in the address storage device and then for applying error detection signals generated by the error detection generation means to the modulation input of the voltage controlled oscillator at an amplitude less than the amplitude of the chip code applied to the modulation input by the chip code generator means.

55. The spread spectrum transmitter according to claim 52, further comprising:

means for applying the chip code signal to the modulation input of the voltage controlled oscillator so that the output of the voltage controlled oscillator produces a frequency shift keying spread spectrum signal as said output signal at said carrier frequency.

56. The spread spectrum transmitter according to claims 52, 53 or 55, further comprising:

an address storage device for storing addresses;

error detection generation means for detecting data errors in data to be transmitted; and

means for applying, simultaneous with said chip code signal, addresses stored in the address storage device and then for applying error detection signals generated by the error detection generation means to the modulation input of the voltage controlled oscillator at an amplitude less than the amplitude of the chip code signal applied to the oscillator means.

57. The spread spectrum transmitter according to claims 52, 53 or 55, wherein:

said voltage controlled oscillator comprises an enable input; and

said transmitter further comprises,

a power amplifier, having an enable input, for amplifying the output of the voltage controlled oscillator, and,

control means connected to the enable input of the voltage controlled oscillator and the enable input of the power amplifier for enabling said voltage controlled oscillator and said power amplifier to operate in respective active states only during a transmission from the transmitter, thereby reducing power drain and ensuring adequate oscillator settling time.

58. The spread spectrum transmitter according to claim 57, wherein:

said control means for providing a delay prior to enabling the input of the power amplifier, thereby allowing a timing reference of the chip code generator means to settle prior to a transmission.

62. The spread spectrum transmitter according to claims 52, 53 or 55, further comprising:

modulation index setting means for setting a frequency deviation of the voltage controlled oscillator in response to modulating signals applied to the modulation input of the voltage controlled oscillator to generate fast frequency shift keying (FFSK) in order to minimize transmitted bandwidth.

69. The spread spectrum transmitter according to claims 52 or 53, further comprising:

means for providing message redundancy by generating and applying plural transmit messages to said modulation input for transmission by the transmitter;

said voltage controlled oscillator having an enable input;

a power amplifier having an enable input and configured to amplify the output of said voltage controlled oscillator; and

control means connected to the enable input of said voltage controlled oscillator and the enable input of said power amplifier for enabling respective operational states of said voltage controlled oscillator and said power amplifier only during a transmission from the transmitter, thereby reducing power drain and ensuring adequate settling time.

70. The spread spectrum transmitter according to claim 69, wherein:

said control means provides a delay prior to enabling said power amplifier, thereby allowing a timing reference of the chip code generator means to settle prior to a transmission.

71. A spread spectrum system comprising:

a spread spectrum transmitter comprising,

oscillator means, including a voltage controlled oscillator having a modulation input, for generating an output signal at a carrier frequency,

processor means for controlling transmissions of said output signal from the voltage controlled oscillator, said processor means including processor oscillator means for producing a frequency stabilizing reference clock signal,

means for stabilizing the frequency of the voltage controlled oscillator by locking the frequency of the voltage controlled oscillator to the frequency stabilizing reference clock signal produced by said processor oscillator means,

timer means for defining an active operating state in which the processor means and the voltage controlled oscillator are enabled in an active state, said timer means first enabling said processor oscillator means to operate for a predetermined time to stabilize the frequency output of the processor oscillator means and thereafter enabling said voltage controlled oscillator to operate for the predetermined time to allow the frequency output of the voltage controlled oscillator to stabilize, said timer means also defining an inactive state in which the processor means is not enabled and the voltage controlled oscillator is not enabled and the output signal is not produced at the carrier frequency, and

said processor means further comprising chip code generator means clocked by the processor oscillator means for generating a chip code signal applied to the oscillator means, and thereby locking the carrier frequency to the chip code signal as a result of the voltage controlled oscillator and the chip code generator means sharing a common reference oscillator; and

a receiver means limiting RF bandwidth energy to approximately 2 MHZ prior to despreading;

wherein said chip code generator means generates a chip code sequence repetition at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce at least one of a frequency shift keying (FSK) spread spectrum modulated signal and a phase shift keying spread spectrum signal.

72. A spread spectrum transmitter comprising:

carrier generation means for generating a modulated carrier signal, said carrier generation means including a modulation input for application thereto of a modulating signal;

a power amplifier, having an enable input, that amplifies the modulated carrier signal generated by said carrier generation means;

a filter connected to an output of the power amplifier that filters the output of the power amplifier;

an antenna connected to an output of the filter;

processor means for controlling transmissions by said carrier generation means, including,

processor oscillator means for producing a reference for stabilizing the modulated carrier signal,

means for stabilizing the modulated carrier signal using the reference signal produced by said processor oscillator means, and

chip code generator means clocked by the processor oscillator means for producing a chip code signal applied to the modulation input of said carrier generation means, thereby producing at the antenna a spread spectrum carrier frequency which is locked to the chip code generator means;

timer means for defining a low current inactive mode and an active operating mode in which the processor means, the carrier generation means and the amplifier are enabled;

wake-up means having an external input and a timer input from said timer means for enabling said active operating mode of said processor means, said carrier generation means and said power amplifier in accordance with the external input and the timer input; and

said processor means further comprising means for providing transmitted message redundancy by generating plural active mode transmit messages.

73. The spread spectrum transmitter according to claim 72, wherein said carrier generation means comprises:

a tuned oscillator; and

a phase shift keying modulator coupled to said tuned oscillator and having said modulation input modulated by said processor means to produce a phase shift keying modulated signal.

74. The spread spectrum transmitter according to claim 72, wherein said processor means further comprises:

means for applying a data message to the modulation input of said carrier generation means; and

means for selecting a data rate and a chip rate for a given length of the data message such that once initial spread spectrum synchronization is achieved by a receiver, the receiver can receive without performing continuous chip code synchronization.

75. The spread spectrum transmitter according to claims 72 or 74, wherein said carrier generation means comprises:

a voltage controlled oscillator having the modulation input modulated by said processor means to produce a frequency shift keying modulated signal.

76. The spread spectrum transmitter according to claim 74, wherein said carrier generation means comprises:

a tuned oscillator; and

a phase shift keying modulator coupled to said tuned oscillator and having said modulation input modulated by said processor means to produce a phase shift keying modulated signal.

77. The spread spectrum transmitter according to claims 72 or 74, wherein:

said chip code generator means generates a chip code sequence at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a frequency shift keying spread spectrum modulated signal.

78. The spread spectrum transmitter according to claims 73 or 76, wherein:

said chip code generator means generates a chip code sequence at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a phase shift keying spread spectrum modulated signal.

79. A spread spectrum transmit only device comprising:

oscillator means, including a voltage controlled oscillator having a modulation input, for generating a transmitter output at a carrier frequency;

processor means for controlling transmissions by the voltage controlled oscillator, said processor means including processor oscillator means for producing a frequency stabilizing reference clock signal;

means for stabilizing the frequency of the voltage controlled oscillator by locking the frequency of the voltage controlled oscillator to the frequency stabilizing reference clock signal produced by said processor oscillator means; and

said processor means further comprising chip code generator means clocked by the processor oscillator means for generating a chip code signal applied to the oscillator means, thereby generating the chip code signal in a fixed relationship with the carrier frequency.

80. The transmit only device according to claim 79, wherein:

said chip code generator means generates a chip code sequence repetition at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a frequency shift keying spread spectrum modulated signal.

81. The transmit only device according to claim 79, wherein said oscillator means includes:

a tuned oscillator; and

a phase shift keying modulator having the modulation input and coupled to said tuned oscillator and having said modulation input modulated by said processor means to produce a phase shift keying modulated signal.

82. The transmit only device according to claim 81, wherein:

said chip code generator means generates a chip code sequence repetition at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a phase shift keying spread spectrum modulated signal.

84. A spread spectrum transmitter comprising:

an oscillator having a modulation input and configured to produce at an output thereof a variable frequency output tuned to a carrier frequency;

a processor configured to perform a computer-based chip code generator process that produces a chip code and applies the chip code to the modulation input of the oscillator so as to change the frequency output of the oscillator to directly produce a spread spectrum frequency shift keying (FSK) modulated signal at said carrier frequency;

a power amplifier connected to the output of the oscillator and configured to produce an amplified spread spectrum FSK modulated signal at said carrier frequency, said power amplifier having an output;

a bandpass filter coupled to the output of the power amplifier to produce a bandpass filtered amplified spread spectrum FSK modulated signal at said carrier frequency at an output thereof; and

an antenna coupled to the output of the bandpass filter for transmitting the filtered amplified spread spectrum FSK modulated signal at said carrier frequency.

85. A spread spectrum transmitter comprising:

a voltage controlled oscillator having a modulation input and an output that provides a frequency output tuned to a preselected carrier frequency;

a processor configured to generate and apply a chip code sequence to the modulation input so as to modulate the frequency output of the voltage controlled oscillator to generate a spread spectrum signal; and

a memory coupled to the modulation input of the voltage controlled oscillator and configured to simultaneously apply data stored therein to the modulation input of the voltage controlled oscillator,

wherein a modulation frequency deviation of said data is less spectrally broad than a modulation frequency deviation of said chip code sequence.

86. A spread spectrum transmitter comprising:

a carrier generation device configured to generate a carrier at a carrier frequency at an output thereof;

a phase shift keying modulator having an input coupled to the output of the carrier generation device and having a modulation input;

a chip code generator connected to the modulation input of the phase shift keying modulator and configured to apply a chip code sequence to the modulation input of the phase shift keying modulator and thereby produce a phase shift keying spread spectrum modulated signal at said carrier frequency at an output of said phase shift keying modulator;

a power amplifier having an input coupled to an output of the phase shift keying modulator and an output that provides an amplified phase shift keying spread spectrum signal;

a filter having an output and an input coupled to the output of the power amplifier;

an antenna coupled to the output of the filter and configured to transmit an amplified and filtered phase shift keying spread spectrum modulated signal at said carrier frequency;

a timer that determines when multiple chip code sequences are applied to the modulation input of the phase shift keying modulator prior to transmission of data, thereby to promote spread spectrum timing synchronization in a receiver configured to receive the spread spectrum modulated signal transmitted by the antenna;

a first memory that stores addresses;

a second memory that stores data; and

an error detector that outputs a plurality of error detection bits to secure at least one of the addresses stored in said first memory and the data stored in said second memory, said plurality of error detection bits to be transmitted with said data and said at least one of the addresses.

87. A spread spectrum transmitter comprising:

a carrier frequency generation device that generates a carrier frequency at an output thereof;

a frequency stabilizing loop connected to said carrier frequency generation device and configured to reduce a frequency offset error at the output of the carrier frequency generation device;

a phase shift keying modulator having an input coupled to the output of the carrier frequency generation device and having a modulation input;

a chip code generator connected to the modulation input of the phase shift keying modulator and configured to apply a chip code sequence to the modulation input of the phase shift keying modulator and thereby produce a phase shift keying spread spectrum modulated signal at the carrier frequency of the carrier frequency generation device at an output of said phase shift keying modulator;

a power amplifier having an input coupled to an output of the phase shift keying modulator and an output that provides an amplified phase shift keying spread spectrum signal;

a filter having an output and an input coupled to the output of the power amplifier;

an antenna coupled to the output of the filter and configured to transmit an amplified and filtered phase shift keying spread spectrum modulated signal at a desired transmitted frequency;

a timer that determines when said chip code generator applies one or more chip code sequences to the modulation input of the phase shift keying modulator prior to transmission of data, thereby to promote spread spectrum synchronization in a receiver configured to receive a spread spectrum modulated signal transmitted by the antenna;

a first memory that stores at least one address;

a second memory that stores data; and

an error detector that provides a plurality of error detection bits to secure the data and said at least one address to be transmitted,

said at least one address stored in the first memory, data stored in the second memory, and error detection signals generated by the error detector being applied to the modulation input of the phase shift keying modulator, thereby sequentially outputting address, data and error detection signals.

88. A spread spectrum transmitter comprising:

an oscillator, including a voltage controlled oscillator having a modulation input, configured to output an output signal at a carrier frequency;

a processor that controls transmissions of the output signal from the oscillator, said processor including a processor oscillator device that produces a frequency stabilizing reference clock signal;

a frequency stabilization device that stabilizes the frequency of the voltage controlled oscillator by locking the frequency of the oscillator to the frequency stabilizing reference clock signal produced by said processor oscillator device;

a timer that determines when to enable an active operating state of the processor oscillator device and the oscillator, said timer first enabling said processor oscillator device for a predetermined time to stabilize the frequency output of the processor oscillator device and thereafter enabling said oscillator for another predetermined time to allow the frequency output of the oscillator to stabilize, said timer also defining an inactive state in which the processor oscillator device is not enabled and the oscillator is not enabled and no carrier frequency at the transmitter output is produced; and

said processor further including a chip code generator that is clocked by the processor oscillator device and that generates a chip code signal applied to the processor oscillator device, so as to lock the carrier frequency to the chip code signal as a result of the oscillator and the chip code generator sharing a common reference oscillator.

89. A spread spectrum transmitter comprising:

a carrier generation device, having a modulation input, that generates a modulated carrier signal in response to a modulating signal applied to the modulation input;

a power amplifier, having an enable input, that amplifies the modulated carrier signal;

a filter that filters an amplified signal output from the power amplifier;

an antenna connected to an output of the filter;

a processor that controls transmissions of the modulated carrier signal provided by said carrier generation device, including,

a processor oscillator device that produces a reference signal which stabilizes the modulated carrier signal,

a stabilization device that stabilizes the modulated carrier signal with the reference signal produced by said processor oscillator device, and

a chip code generator clocked by the processor oscillator device and configured to produce a chip code signal applied to the modulation input of said carrier generation device, thereby producing at the antenna a spread spectrum carrier frequency which is locked to the chip code generator;

a timer for defining when a low current inactive mode and an active operating mode occur in the processor, the carrier generation device and the power amplifier; and

a wake-up device having an external input and a timer input from said timer which enables said processor, said carrier generation device and said power amplifier in accordance with the external input and the timer input, and

said processor oscillator device including a retransmission device that generates plural active mode transmit messages thereby providing transmitted message redundancy.

90. A spread spectrum transmit only device comprising:

an oscillator, including a voltage controlled oscillator having a modulation input, that generates a transmitter output at a carrier frequency;

a processor that controls transmissions of the output signal from the voltage controlled oscillator, said processor including a processor oscillator device that produces a frequency stabilizing reference clock signal; and

a frequency stabilization device that stabilizes the frequency of the voltage controlled oscillator by locking the frequency of the voltage controlled oscillator to the frequency stabilizing reference clock signal produced by said processor oscillator device, wherein

said processor further includes a chip code generator clocked by the processor oscillator device that generates a chip code signal applied to the oscillator, thereby generating the chip code signal in a fixed relationship with the carrier frequency.

91. A spread spectrum system comprising:

a transmitter comprising chip code generator means for applying a chip code signal to a modulation input of a voltage controlled oscillator so that an output of the voltage controlled oscillator produces a frequency shift keying spread spectrum signal at a carrier frequency; and

a receiver means for limiting RF front end bandwidth to 2 MHZ;

wherein said chip code generator means generates a chip code sequence repetition at a chip rate of approximately 1.0 MHZ to 1.3 MHZ to produce a frequency shift keying spread spectrum modulated signal.

92. A spread spectrum system comprising:

a transmitter having a carrier generation device configured to generate a carrier at a carrier frequency at an output thereof,

a phase shift keying modulator having an input coupled to the output of the carrier generation device and having a modulation input;

a chip code generator connected to the modulation input of the phase shift keying modulator and configured to apply a chip code sequence to the modulation input of the phase shift keying modulator and thereby produce a phase shift keying spread spectrum modulated signal at said carrier frequency at an output of said phase shift keying modulator;

a power amplifier having an input coupled to an output of the phase shift keying modulator and an output that provides an amplified phase shift keying spread spectrum signal;

a filter having an output and an input coupled to the output of the power amplifier;

an antenna coupled to the output of the filter and configured to transmit an amplified and filtered phase shift keying spread spectrum modulated signal at said carrier frequency;

a timer that determines when multiple chip code sequences are applied to the modulation input of the phase shift keying modulator prior to transmission of the data, thereby to promote spread spectrum timing synchronization in a receiver configured to receive the spread spectrum modulated signal transmitted by the antenna;

a first memory that stores addresses;

a second memory that stores data;

an error detector that outputs a plurality of error detection bits to secure the data stored in said second memory and at said addresses, said error detection bits to be transmitted with said data; and

the receiver having a bandwidth limiting device coupled to a despreading device, said receiver producing an approximately 2 MHZ bandlimited received spread spectrum signal to the despreading device;

said despreading device configured to receive a signal containing at least information matching a pattern of the chip code sequence as produced by the chip code generator of the transmitter so as to produce a despreading signal.

93. A spread spectrum system comprising:

a transmitter having an oscillator with a modulation input and configured to produce at an output thereof a variable frequency output tuned to a carrier frequency;

a chip code generator that produces a chip code sequence and applies the chip code sequence to the modulation input of the oscillator so as to change the frequency output of the oscillator to directly produce a spread spectrum frequency shift keying (FSK) modulated signal at said carrier frequency;

a power amplifier connected to the output of the oscillator and configured to produce an amplified spread spectrum FSK modulated signal at said carrier frequency, said power amplifier having an output;

a bandpass filter coupled to the output of the power amplifier so as to produce a bandpass filtered amplified spread spectrum FSK modulated signal at said carrier frequency at an output thereof;

an antenna coupled to the output of the bandpass filter for transmitting the filtered amplified spread spectrum FSK modulated signal at said carrier frequency;

a receiver having a bandwidth limiting device configured to produce an approximately 2 MHZ bandlimited received spread spectrum signal;

a despreading device coupled to an output of the bandwidth limiting device and configured to receive a signal containing at least information matching a pattern of the chip code sequence as produced by the chip code generator of the transmitter an configured to produce a despreading signal.

94. A spread spectrum transmitter comprising:

a carrier generation device configured to generate a carrier at a carrier frequency at an output thereof;

a phase shift keying modulator having an input coupled to the output of the carrier generation device and having a modulation input;

a processor that controls transmissions of an output signal from the carrier generation device, said processor including a processor oscillator device that produces a frequency stabilizing reference clock signal at an output thereof;

a frequency stabilization device that stabilizes the frequency of the carrier generation device by locking the frequency of the carrier generation device to the frequency stabilizing reference clock signal produced by said processor oscillator device; and

a timer that determines when to enable an active operating state of the processor oscillator device and the carrier generation device, said timer first enabling said processor oscillator device for a predetermined time so as to stabilize a frequency output by the processor oscillator device and thereafter enabling said carrier generation device for another predetermined time so as to allow the frequency output of the carrier generation device to stabilize, said timer also defining an inactive state in which the processor oscillator device is not enabled and the carrier generation device is not enabled and no carrier frequency at the transmitter output is produced;

wherein

said processor further comprises a chip code generator that is clocked by the processor oscillator device and that generates a chip code signal applied to the processor oscillator device, so as to lock the carrier frequency to the chip code signal as a result of the carrier generation device and the chip code generator sharing a common reference oscillator.

95. A spread spectrum transmitter comprising:

a carrier generation device configured to generate a carrier signal at a carrier frequency at an output thereof,

a phase shift keying modulator having an input coupled to the output of the carrier generation device and having a modulation input;

a power amplifier, having an enable input, that amplifies the carrier signal;

a filter that filters an amplified signal output from the power amplifier;

an antenna connected to an output of the filter;

a processor that controls transmissions of the carrier signal provided by said carrier generation device, including,

a processor oscillator device that produces a reference signal which stabilizes the carrier signal,

a stabilization device that stabilizes the carrier signal with the reference signal produced by said processor oscillator device, and

a chip code generator clocked by the processor oscillator device and configured to produce a chip code signal applied to the modulation input of said carrier generation device, thereby producing at the antenna a spread spectrum carrier frequency which is locked to the chip code generator;

a timer for defining when a low current inactive mode and an active operating mode in the processor oscillator device, the carrier generation device and the power amplifier; and

a wake-up device having an external input and a timer input that receives a timer signal from said timer which enables said processor, said carrier generation device and said power amplifier in accordance with the external input and the timer signal, wherein

said processor oscillator device includes a retransmission device that generates plural active mode transmit messages, thereby providing transmitted message redundancy.