Multi-band, multi-mode spread-spectrum communication system

• US 5,815,525 A
• Filed: 03/27/1996
• Issued: 09/29/1998
• Est. Priority Date: 05/13/1991
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Omnipoint Corp. (Deutsche Telekom AG)
• Inventors: Dixon, Robert C., Smith, Douglas G., Vanderpool, Jeffrey S.
• Primary Examiner(s): Bocure, Tesfaldet
• Application Number:
  US08/622,812
• Time in Patent Office: 916 Days
• Field of Search: 375/200, 375/216, 375/219, 375/295, 375/316, 455/188.1, 455/266, 455/33.1, 379/59, 379/61
• US Class Current: 375/130
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band
• CPC Class Codes: H04B 1/006 using switches for selecting the desired band H04B1/0057 takes precedence
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 2201/7071 with dynamic control of receiver resources
• CPC Class Codes: H04B 7/2634 for channel frequency control
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate

Abstract

A technique for spread-spectrum communication which uses more than one mode and more than one frequency band. Selectable modes include narrowband mode and spread-spectrum mode, or cellular mode and microcellular mode. Selectable frequency bands include both licensed and unlicensed frequency bands, particularly frequency bands including the 902-928 MHz, 1850-1990 MHz, and 2.4-2.4835 GHz frequency bands. Spread-spectrum communication channels are 10 MHz or less in width. The frequency band onto which spread-spectrum signals are encoded may be changed upon a change in environment or other control trigger, such as establishment or de-establishment of communication with a private access network.

Claims

1. A transmitter comprising:

a mode controller for selecting between a first fixed mode and a second fixed mode,

a spread-spectrum modulator, responsive to said first fixed mode of said mode controller, for generating a spread-spectrum signal, and

a narrowband modulator, responsive to said second fixed mode of said mode controller, for generating a narrowband signal wherein one of said narrowband signal and said spread spectrum signal is transmitted in a cellular region, and the other of said narrowband signal and said spread spectrum signal is transmitted in a microcellular region.

2. The transmitter of claim 1 further comprising a cordless telephone.

3. The transmitter of claim 1 wherein said spread-spectrum signal and said narrowband signal occupy at least partially overlapping frequency bands.

4. The transmitter of claim 1 wherein said spread-spectrum signal and said narrowband signal occupy separate and distinct frequency bands.

5. The transmitter of claim 1 further comprising a paging unit.

6. The transmitter of claim 1 further comprising an antenna shared with a receiver.

7. The transmitter of claim 1 further comprising an adjustable bandpass filter responsive to said first fixed mode for passing said narrowband modulated signal, and responsive to said second fixed mode for passing said spread-spectrum signal.

8. The transmitter of claim 1 further comprising a bandpass filter having a bandwidth capable of passing both said spread-spectrum signal and said narrowband signal.

9. The transmitter of claim 1 further comprising a means for generating a carrier signal.

10. The transmitter of claim 9 wherein said means for generating a carrier signal comprises a tunable frequency synthesizer.

11. The transmitter of claim 4 further comprising a power amplifier coupled to said spread-spectrum modulator and said narrowband modulator, wherein said power amplifier may be adjusted to operate in the frequency band corresponding to either said first fixed mode or said second fixed mode.

12. A receiver comprising:

a mode controller for selecting between a first fixed mode and a second fixed mode,

a spread-spectrum demodulator, responsive to said first fixed mode of said mode controller, for demodulating a received spread-spectrum signal, and

a narrowband demodulator, responsive to said second fixed mode of said mode controller, for demodulating a received narrowband signal wherein one of said received spread-spectrum signal and said received narrowband signal is received in a cellular region and the other of said received narrowband signal and received spread-spectrum signal is received in a microcellular region.

13. The receiver of claim 12 further comprising a band pass filter for filtering a received signal.

14. The receiver of claim 13 wherein said bandpass filter is adjustable.

15. The receiver of claim 14 wherein said bandpass filter is shared with a transmitter.

16. The receiver of claim 12 further comprising a frequency converter for generating an intermediate frequency signal from a received signal.

17. The receiver of claim 16 further comprising a frequency synthesizer, wherein said frequency converter generates said intermediate frequency signal by multiplying said received signal with an output of said frequency synthesizer.

18. The receiver of claim 12 further comprising a paging unit.

19. A transmitter comprising a mode controller for selecting from among a plurality of modulators, at least one of said modulators being a narrowband modulator and at least one of said modulators being a spread-spectrum modulator, wherein the narrowband modulator operates within a cellular system and the spread spectrum modulator operates within a microcellular system.

20. A transmitter comprising

a switch for selecting between two modes,

means responsive to a first of said two modes for transmitting in a cellular region,

means responsive to a second of said two modes for transmitting in a microcellular region,

wherein said means for transmitting in a cellular region further comprises means for generating a narrowband signal and said means for transmitting in a microcellular region further comprises means for generating a spread-spectrum signal.

21. A telephone comprising

a switch for selecting between a first mode and a second mode, and

a transmitter for transmitting in a cellular region in response to selecting said first mode and for transmitting in a microcellular region in response to selecting said second mode,

wherein said transmitter transmits a spread-spectrum signal in at least one of said first mode and said second mode and said transmitter transmits a narrowband signal in the other of said first mode and said second mode.

22. The telephone of claim 21, wherein the frequency band used by said transmitter when transmitting in said cellular region and the frequency band used by said transmitter when transmitting in said microcellular region at least partially overlap.

23. The telephone of claim 21, wherein the frequency band used by said transmitter when transmitting in said cellular region and the frequency band used by said transmitter when transmitting in said microcellular region are separate and distinct.

24. The telephone of claim 21, further comprising an adjustable bandpass filter capable of passing either a spread-spectrum signal or a narrowband signal.

25. A receiver comprising

a mode controller for selecting between narrowband modulation and spread-spectrum modulation,

an adjustable bandpass filter, responsive to a narrowband modulation setting of said mode controller for passing a narrowband signal, and responsive to a spread-spectrum setting of said mode controller for passing a spread-spectrum signal,

a spread-spectrum demodulator for demodulating said spread-spectrum signal, and

a narrowband demodulator for demodulating said narrowband signal wherein one of said narrowband signal and said spread spectrum signal is received in a microcellular region and the other of said narrowband signal and said spread spectrum signal is received in a cellular region.

26. A cordless telephone comprising

a mode controller for selecting between a first mode and a second mode,

a transmitter, responsive to said first mode of said mode controller for generating a spread-spectrum signal, and responsive to said second mode of said mode controller for generating a narrowband signal, and

a receiver, responsive to said first mode of said mode controller for receiving a spread-spectrum signal, and responsive to said second mode of said mode controller for receiving a narrowband signal wherein one of the spread spectrum signal and the narrowband signal is transmitted and received in a cellular region and the other of the spread spectrum and the narrowband signal is transmitted and received in a microcellular region.

27. A method for communication comprising the steps of

selecting between a narrowband mode and a spread-spectrum mode,

generating, in response to said narrowband mode, a narrowband signal,

generating, in response to said spread-spectrum mode, a spread-spectrum signal,

transmitting one of said narrowband signal and said spread-spectrum signal in a cellular region, and

transmitting the other of said narrowband signal and said spread-spectrum signal in a microcellular region.