System and process for shared functional block communication transceivers with GPS capability

• US 6,208,844 B1
• Filed: 02/23/1999
• Issued: 03/27/2001
• Est. Priority Date: 02/23/1999
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Conexant Systems Incorporated (Synaptics Incorporated)
• Inventors: Abdelgany, MohyEldeen Fouad
• Primary Examiner(s): MAUNG, NAY AUNG
• Application Number:
  US09/256,450
• Time in Patent Office: 763 Days
• Field of Search: 455/82, 455/83, 455/118, 455/456, 455/556, 455/562, 455/404, 342/357.12, 343/725, 343/729, 370/320
• US Class Current: 455/82
• CPC Class Codes: G01S 19/35 Constructional details or hardware or software details of the signal processing chain
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers

Abstract

A communication system capable of communicating RF signals at any one of a plurality of communication standards through a common antenna is disclosed. The communication system includes a transmitting unit having at least one transmit RF information signal output, and a receiving unit having at least one receive RF information signal input and a GPS RF information signal input. The transmitting unit includes a modulator for modulating a transmit IF with a transmit baseband information signal to generate a transmit IF information signal and an upconverter for upconverting the transmit IF information signal with a transmit RF to generate at least one transmit RF information signal. The receiving unit includes a receive downconverter for downconverting the at least one receive RF information signal with a receive RF to generate a receive IF information signal, a GPS downconverter for downconverting the GPS RF information signal with the receive RF to generate a GPS IF information signal, and a demodulator for demodulating the receive IF information signal and the GPS IF information signal with a receive IF to generate GPS and receive baseband signals. An antenna is coupled to the at least one transmit RF information signal output, the at least one receive RF information signal input, and the GPS RF information signal input for transmitting and receiving RF information signals.

Claims

1. A communication system for communicating first information signals at any one of a plurality of communication standards through a common antenna, the communication system comprising:

a transmitting unit having a modulator for modulating a transmit second local oscillator (LO) frequency with a transmit baseband information signal to generate a transmit second information signal, an upconverter for upconverting the transmit second information signal with a transmit first LO frequency to generate at least one transmit first information signal, and at least one transmit first information signal output for communicating the at least one transmit first information signal;

a receiving unit having at least one receive first information signal input for communicating at least one receive first information signal and a Global Positioning System (GPS) first information signal input for communicating a GPS first information signal, the receiving unit having at least one receive downconverter for downconverting the at least one receive first information signal with a receive first LO frequency to generate a receive second information signal, a GPS downconverter for downconverting the GPS first information signal with the receive first LO frequency to generate a GPS second information signal, and a demodulator for demodulating the receive second information signal and the GPS second information signal with a receive second LO frequency to generate GPS and receive baseband signals; and

an antenna coupled to the at least one transmit first information signal output, the at least one receive first information signal input, and the GPS first information signal input for transmitting and receiving first information signals.

2. A communication system as recited in claim 1, further including a GPS processor coupled for receiving the GPS baseband signals, the GPS processor having a GPS engine for performing GPS processing and acquisition.

3. A communication system as recited in claim 1, further including a Coleman filter coupled for receiving the GPS baseband signals, the Coleman filter having a matched filter for despreading the GPS baseband signals and providing E911 support.

4. A communication system as recited in claim 1, wherein one of the plurality of communication standards is Code Division Multiple Access (CDMA).

5. A communication system as recited in claim 1, the receiving unit further including a common second variable gain amplifier coupled for receiving the receive second information signal and the GPS second information signal, the common second variable gain amplifier for amplifying and transmitting the receive second information signal and the GPS second information signal to the demodulator, the common second variable gain amplifier having a dynamic range of about 90 dB.

6. A communication system as recited in claim 5, the receiving unit further including a GPS first low noise amplifier coupled between the antenna and the GPS downconverter for amplifying the GPS first information signal received from the antenna, the GPS first low noise amplifier having a noise figure of about 1.5 dB and a gain of about 20 dB.

7. A communication system as recited in claim 6, the receiving unit further including a preselector filter coupled between the antenna and the GPS first low noise amplifier for filtering the GPS first information signal received from the antenna, the preselector filter having a passband of about 1574.42-1576.42 MHz.

8. A communication system as recited in claim 6, the receiving unit further including a GPS first image reject filter coupled between the GPS first low noise amplifier and the GPS downconverter for filtering image frequencies generated by the GPS first low noise amplifier, the GPS first image reject filter having a passband of about 1574.42-1576.42 MHz.

9. A communication system as recited in claim 5, the receiving unit further including a GPS narrowband second filter coupled between the GPS downconverter and the common second variable gain amplifier for filtering spurious frequencies generated by the GPS downconverter, the GPS narrowband second filter having a bandwidth of about 2 MHz.

10. A communication system as recited in claim 1, further including a common first frequency source for generating the receive first LO frequency, wherein the at least one receive downconverter mixes the at least one receive first information signal with the receive first LO frequency to produce the receive second information signal, and the GPS downconverter mixes the GPS first information signal with the receive first LO frequency to produce the GPS second information signal.

11. A communication system as recited in claim 1, further including a common second frequency source for generating the receive second LO frequency, wherein the demodulator mixes the receive second information signal with the receive second LO frequency to produce the receive baseband signals, and mixes the GPS second information signal with the receive second LO frequency to produce the GPS baseband signals.

12. A communication system as recited in claim 1, further including a common first frequency source for generating the receive first LO frequency and the transmit first LO frequency, wherein the at least one receive downconverter mixes the at least one receive first information signal with the receive first LO frequency to produce the receive second information signal, the GPS downconverter mixes the GPS first information signal with the receive first LO frequency to produce the GPS second information signal, and the upconverter mixes the transmit second information signal with the transmit first LO frequency to produce the at least one transmit first information signal.

13. A communication system as recited in claim 1, further including a common second frequency source for generating the receive second LO frequency and the transmit second LO frequency, wherein the demodulator mixes the receive second information signal with the receive second LO frequency to produce the receive baseband signal and mixes the GPS second information signal with the receive second LO frequency to produce the GPS baseband signal, and wherein the modulator mixes the transmit baseband information signal with the transmit second LO frequency to produce the transmit second information signal.

14. A communication system receiving unit as recited in claim 1, further including a GPS processor for receiving the GPS baseband signals, the GPS processor comprising a GPS engine for performing GPS processing and acquisition.

15. A communication system receiving unit as recited in claim 1, further comprising a Coleman filter coupled for receiving the GPS baseband signals, the Coleman filter having a matched filter for despreading the GPS baseband signals and providing E911 support.

16. A process for communicating first information signals at any one of a plurality of communication standards through a common antenna, the process comprising:

modulating a transmit second LO frequency with a transmit baseband information signal to generate a transmit second information signal, upconverting the transmit second information signal with a transmit first LO frequency to generate at least one transmit first information signal, and transmitting the at least one transmit first information signal through the antenna;

receiving at least one receive first information signal from the antenna, downconverting the at least one receive first information signal with a receive first LO frequency to generate a receive second information signal, and demodulating the receive second information signal with a receive second LO frequency to generate a receive baseband information signal; and

receiving a GPS first information signal from the antenna, downconverting the GPS first information signal with the receive first LO frequency to generate a GPS second information signal, and demodulating the GPS second information signal with the receive second LO frequency to generate a GPS baseband information signal.

17. A process as recited in claim 16, further including the steps of:

filtering the receive baseband signals to remove out of band frequencies and quantizing the receive baseband signals; and

filtering the GPS baseband signals to remove out of band frequencies and quantizing the GPS baseband signals.

18. A process as recited in claim 17, wherein preceding the step of filtering the GPS baseband signals to remove out of band frequencies, the process further includes the step of Coleman filtering the GPS baseband signals for despreading the GPS baseband signals and providing E911 support.

19. A process as recited in claim 17, wherein following the step of quantizing the GPS baseband signals, the process further includes the step of performing GPS processing and acquisition on the quantized GPS baseband signals.

20. A communication system for communicating first information signals at any one of a plurality of communication standards through a common antenna, the communication system comprising:

means for modulating a transmit second LO frequency with a transmit baseband information signal to generate a transmit second information signal, upconverting the transmit second information signal with a transmit first LO frequency to generate at least one transmit first information signal, and transmitting the at least one transmit first information signal through the antenna;

means for receiving at least one receive first information signal from the antenna, downconverting the at least one receive first information signal with a receive first LO frequency to generate a receive second information signal, and demodulating the receive second information signal with a receive second LO frequency to generate a receive baseband information signal; and

means for receiving a GPS first information signal from the antenna, downconverting the GPS first information signal with the receive first LO frequency to generate a GPS second information signal, and demodulating the GPS second information signal with the receive second LO frequency to generate a GPS baseband information signal.

21. A system as recited in claim 20, further including:

means for filtering the receive baseband signals to remove out of band frequencies and quantizing the receive baseband signals; and

means for filtering the GPS baseband signals to remove out of band frequencies and quantizing the GPS baseband signals.

22. A system as recited in claim 21, further including means for Coleman filtering the GPS baseband signals for despreading the GPS baseband signals and providing E911 support, the means for Coleman filtering the GPS baseband signals coupled between the means for demodulating the GPS second information signal with the receive second LO frequency and the means for filtering the GPS baseband signals.

23. A system as recited in claim 21, further including means for performing GPS processing and acquisition on the quantized GPS baseband signals, the means for performing GPS processing and acquisition coupled to the means for quantizing the GPS baseband signals.

24. A communication system receiving unit for receiving a first information signal via a common antenna comprising:

a first information signal input for receiving the first information signal, and a global positioning system (GPS) information signal input for receiving a GPS first information signal,

a downconverter for downconverting the first information signal in accordance with a receive first local oscillator frequency to generate a second information signal,

a GPS downconverter for downconverting the GPS information signal in accordance with the receive first local oscillator frequency to generate a second GPS information signal, and

a demodulator for demodulating the second information signal and the second GPS information signal with a receive second local oscillator frequency to generate GPS and receive baseband signals.

25. A process for receiving a first information signal via a common antenna comprising:

receiving a first information signal from the common antenna;

downconverting the received first information signal with a receive first local oscillator frequency to generate a receive second information signal;

demodulating the receive second information signal with a receive second local oscillator frequency to generate a receive baseband information signal;

receiving a GPS first information signal from the antenna;

downconverting the GPS first information signal with the receive first local oscillator frequency to generate a GPS second information signal, and

demodulating the GPS second information signal with the receive second local oscillator frequency to generate a GPS baseband information signal.

26. A process as recited in claim 25, further comprising the steps of:

filtering the receive baseband signals to remove out of band frequencies;

quantizing the and receive baseband signals; and

filtering the GPS baseband signals to remove out of band frequencies and quantizing the GPS baseband signals.

27. A communication system for communicating first information signals at any one of a plurality of communication standards through a common antenna, the communication system comprising:

means for receiving a first information signal from the common antenna, downconverting the receive first information signal with a receive first local oscillator frequency to generate a second information signal, and demodulating the second information signal with a receive second local oscillator frequency to generate a receive baseband information signal; and

means for receiving a first GPS information signal from the antenna, downconverting the first GPS information signal with the receive first local oscillator frequency to generate a second GPS information signal, and demodulating the second GPS information signal with the receive second local oscillator frequency to generate a GPS baseband information signal.

28. A communication system as recited in claim 27, further comprising:

means for filtering the receive baseband signals to remove out of band frequencies and quantizing the receive baseband signals; and

means for filtering the GPS baseband signals to remove out of band frequencies and quantizing the GPS baseband signals.

29. A communication system for transmitting and receiving a first information signal via a common antenna comprising:

a first information signal input for receiving a first information signal, and a global positioning system (GPS) information signal input for receiving a GPS first information signal,

a downconverter for downconverting said first information signal in accordance with a receive first local oscillator frequency to generate a second information signal,

a GPS downconverter for downconverting the GPS information signal in accordance with the receive first local oscillator frequency to generate a second GPS information signal, a demodulator for demodulating the second information signal and the second GPS information signal with a receive second local oscillator frequency to generate GPS and receive baseband signals,

a modulator for modulating said first local oscillator frequency with a baseband information signal to generate a third information signal, and

an upconverter for upconverting the third information signal with a second local oscillator frequency to generate a fourth information signal.

30. A communication system transmitting unit according to claim 29 wherein said transmitting unit transmits said second information signal via a common antenna shared with a global positioning system receiving unit.

31. A communication system transmitting unit according to claim 30 wherein the second information signal comprises a CDMA format information signal.

32. A communication system comprising:

means for receiving a first information signal from a common antenna, downconverting the receive first information signal with a receive first local oscillator frequency to generate a second information signal, and demodulating the second information signal with a receive second local oscillator frequency to generate a receive baseband information signal;

means for receiving a first GPS information signal from the antenna, downconverting the first GPS information signal with the receive first local oscillator frequency to generate a second GPS information signal, and demodulating the second GPS information signal with the receive second local oscillator frequency to generate a GPS baseband information signal;

means for modulating said first local oscillator frequency with a baseband information signal to generate a third information signal,

means for upconverting the third information signal with a second local oscillator frequency to generate a fourth information signal, and

means for outputting said fourth information signal.

33. A communication system transmitting unit according to claim 32 wherein the second information signal conforms to CDMA standards.

34. A communication system transmitting unit according to claim 33 wherein the means for outputting comprises a common antenna shared with a global positioning system.