Universal radio architecture for low-tier personal communication system

• US 5,648,985 A
• Filed: 11/30/1994
• Issued: 07/15/1997
• Est. Priority Date: 11/30/1994
• Status: Expired due to Term

• Current Assignee: Cirrus Logic Incorporated
• Original Assignee: Rockwell Semiconductor Systems Inc. (Synaptics Incorporated)
• Inventors: Madsen, Benny, Gilbert, Sheldon L., Petranovich, James E., Lipowski, Joseph T., Bjerede, Bjorn E.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Le, Amanda T.
• Application Number:
  US08/348,359
• Time in Patent Office: 958 Days
• Field of Search: 329/300, 329/302, 329/304, 329/306, 329/307, 329/316, 348/554, 348/555, 370/11, 370/12, 370/24, 370/29, 370/30, 370/32, 370/39, 370/50, 370/75, 375/216, 375/219, 375/222, 375/223, 375/269, 375/272, 375/273, 375/279, 375/283, 375/295, 375/302, 375/316, 375/322, 375/323, 375/329, 375/330, 375/334, 375/336, 455/73, 455/84-86, 455/89, 455/102, 455/118, 455/142, 455/143, 455/313, 455/314-316, 455/323, 330/1 R, 332/119
• US Class Current: 375/219
• CPC Class Codes: H04B 1/403 using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency
• CPC Class Codes: H04B 1/56 with provision for simultaneous communication in two directions
• CPC Class Codes: H04L 27/0008 arrangements for allowing a transmitter or receiver to use more than one type of modulation negotiating modulation type for two-way transmission paths H04L5/1453
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/1492 with time compression, e.g. operating according to the ping-pong technique

Abstract

An integrated circuit chip set is provided for use in a radio communication system in which a modulated digital input signal is processed for transmission and a modulated signal received from an antenna is processed to provide an output signal, wherein the modulation of the signals is either QPSK or FSK and the signal transmission and reception is by either TDD or FDD. The chip set includes an IF integrated circuit chip for processing a digital input signal to convert the digital input signal into an analog input signal and to provide the input signal at an intermediate frequency and for processing a received signal at the intermediate frequency to down convert the frequency thereof and to provide an output signal from the down-converted received signal; and an RF integrated circuit chip for processing the input signal provided by the IF chip at the intermediate frequency to up convert the frequency thereof to a transmission frequency and for processing a received signal provided at the reception frequency to down convert the frequency thereof to the intermediate frequency. The IF chip includes switches and terminals for enabling the IF chip to be connected for processing by the IF chip of QPSK-modulated signals or to be connected for processing by the IF chip of FSK-modulated signals; and the RF chip includes terminals for enabling the RF chip to be connected for processing by the RF chip of TDD transmitted and received signals or to be connected for processing by the RF chip of FDD transmitted and received signals.

Claims

1. An integrated circuit chip set for use in a radio communication system in which a modulated digital input signal is processed for transmission and a modulated signal received from an antenna is processed to provide an output signal, wherein the modulation of the signals is either quadrature phase shift keying (QPSK) or frequency shift keying (FSK) and the signal transmission and reception is by either time-division duplex (TDD) or frequency-division duplex (FDD), the chip set comprising

an intermediate frequency (IF) integrated circuit chip for processing a digital input signal to convert the digital input signal into an analog input signal and to provide the input signal at an intermediate frequency and for processing a received signal at the intermediate frequency to down convert the frequency thereof and to provide an output signal from the down-converted received signal;

and

a radio frequency (RF) integrated circuit chip for processing the input signal provided by the IF chip at the intermediate frequency to up convert the frequency thereof to a transmission frequency and for processing a received signal provided at the reception frequency to down convert the frequency thereof to the intermediate frequency;

wherein the IF chip and the RF chip in combination include

means for providing the input signal at said intermediate frequency when the modulation of the digital input signal is QPSK modulated and for providing the input signal at said intermediate frequency and/or at the transmission frequency when the modulation of the digital input signal is FSK modulated; and

means for sampling the down-converted received signal to provide said output signal when the down-converted received signal is QPSK modulated and for demodulating the down-converted received signal to provide said output signal when the down-converted received signal is FSK modulated; and

wherein the IF chip includes switches and terminals for enabling the IF chip to be connected for said processing by the IF chip of QPSK-modulated signals or to be connected for said processing by the IF chip of FSK-modulated signals; and

wherein the RF chip includes terminals for enabling the RF chip to be connected for said processing by the RF chip of TDD transmitted and received signals or to be connected for said processing by the RF chip of FDD transmitted and received signals.

2. A chip set according to claim 1, wherein the IF chip includes

a digital-to-analog converter (DAC) for converting the digital input signal into the analog input signal, wherein the output of the DAC is coupled to a first terminal of the IF chip;

a phase-locked loop including a phase-locked oscillator, wherein the input of the phase-locked oscillator is coupled to a second terminal of the IF chip and the output of the phase-locked oscillator is coupled to a third terminal of the IF chip; and

a first mixer having one input coupled to the output of the phase-locked oscillator, a second input coupled to a fourth terminal of the IF chip and an output connected to a fifth terminal of the IF chip;

wherein when the modulation of the digital input signal is QPSK and the first terminal is coupled to the fourth terminal for enabling the first mixer to mix the output of the phase-locked oscillator with the analog input signal, the IF chip is connected for providing to the fifth terminal the input signal at said intermediate frequency; and

wherein when the modulation of the digital input signal is FSK and the first terminal is connected to the second terminal for enabling the input of the phase-locked oscillator to be modulated with the analog input signal, the IF chip is connected for providing the input signal from the output of the phase-locked oscillator to the third terminal at said intermediate frequency.

3. A chip set according to claim 2, wherein the IF chip further includes

a second mixer having one input coupled to a sixth terminal of the IF chip, another input coupled to the output of the phase-locked oscillator and an output coupled to a seventh terminal of the IF chip;

a third mixer having one input coupled to an eighth terminal of the IF chip, another input coupled to a ninth input terminal and an output coupled to a tenth terminal of the IF chip;

a limiting amplifier having an input coupled to an eleventh terminal of the IF chip and an output coupled to a twelfth terminal of the IF chip; and

a sampling circuit having an input connected to a thirteenth terminal of the IF chip and an output connected to a fourteenth terminal of the IF chip;

wherein when the sixth terminal is coupled to the RF chip for receiving the received signal at the intermediate frequency, the second mixer down converts the frequency of the received signal from the intermediate frequency;

wherein when the down-converted received signal is QPSK modulated, the seventh terminal is coupled to the eighth terminal, the ninth terminal is coupled to a reference-frequency signal source, the tenth terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the thirteenth terminal, the IF chip is connected for sampling the down-converted received signal and for providing the sampled signal at the fourteenth terminal; and

wherein when the down-converted received signal is FSK modulated, the seventh terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the eighth terminal through a phase-shifting means and connected directly to the ninth terminal, the IF chip is connected for demodulating the down-converted received signal and for providing the demodulated signal at the tenth terminal.

4. A chip set according to claim 3, wherein the RF chip includes

a first mixer having one input coupled to a first terminal of the RF chip, another input coupled to a second terminal of the RF chip and an output coupled to a third terminal of the RF chip;

and

a second mixer having one input coupled to a fourth terminal of the RF chip, a another input coupled to a fifth terminal of the RF chip and an output coupled to a sixth terminal of the RF chip;

wherein when the transmitted and received signals are TDD transmitted and received signals, the first terminal of the RF chip is coupled to the IF chip for receiving the input signal provided by the IF chip at the intermediate frequency, the second terminal of the RF chip is coupled to a gain control circuit, the third terminal of the RF chip is coupled to the fourth terminal of the RF chip, and the fifth terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the transmission frequency and the intermediate frequency, the RF chip is connected for converting the frequency of the input signal provided by the IF chip to the transmission frequency and for providing the input signal at the transmission frequency at the sixth terminal of the RF chip; and

wherein when the transmitted and received signals are FDD transmitted and received signals, the first terminal of the RF chip is coupled to the IF chip for receiving the input signal provided by the IF chip at the intermediate frequency, the second terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the frequencies of the transmitted signal and the signal received by the antenna, the third terminal of the RF chip is coupled to the fourth terminal of the RF chip and the fifth terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the reception frequency and the intermediate frequency, the RF chip is connected for converting the frequency of the input signal provided by the IF chip to the transmission frequency and for providing the input signal at the transmission frequency at the sixth terminal of the RF chip.

5. A chip set according to claim 4, wherein the RF chip further includes

a third mixer having one input coupled to an seventh terminal of the RF chip, another input coupled to the fifth terminal of the RF chip and an output coupled to an eighth terminal of the RF chip;

wherein when the seventh terminal receives said received signal at the reception frequency, the fifth terminal of the RF chip is coupled to the source of the reference signal having a frequency equal to the difference between the transmission frequency and the intermediate frequency and the transmitted and received signals are TDD transmitted and received signals, the RF chip is connected for converting the frequency of the received signal from the reception frequency to the intermediate frequency and for providing the received signal at the intermediate frequency at the eighth terminal of the RF chip; and

wherein when the seventh terminal receives said received signal at the reception frequency, the fifth terminal of the RF chip is coupled to the source of the reference signal having a frequency equal to the difference between the reception frequency and the intermediate frequency and the transmitted and received signals are FDD transmitted and received signals, the RF chip is connected for converting the frequency of the received signal from the reception frequency to the intermediate frequency and for providing the received signal at the intermediate frequency at the eighth terminal of the RF chip.

6. A chip set according to claim 5, further comprising an amplifier/switch chip, including

a first amplifier having an input coupled to a first terminal of the amplifier/switch chip and an output coupled to a second terminal of the amplifier/switch chip;

a second amplifier having an input coupled to a third terminal of the amplifier/switch chip and an output coupled to a fourth terminal of the amplifier/switch chip;

an antenna terminal; and

a switch for coupling the antenna terminal to either a fifth terminal of the amplifier/switch chip or a sixth terminal of the amplifier/switch chip;

wherein when the transmitted and received signals are TDD transmitted and received signals, the first terminal of the amplifier/switch chip is coupled to the sixth terminal of the RF chip for receiving the input signal provided by the RF chip at the transmission frequency, the second terminal of the amplifier/switch chip is coupled by a low-pass filter to the fifth terminal of the amplifier/switch chip and the switch couples the antenna terminal to the fifth terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the input signal provided by the RF chip at the transmission frequency and for providing the amplified signal to the antenna terminal for transmission;

wherein when the transmitted and received signals are FDD transmitted and received signals, the first terminal of the amplifier/switch chip is coupled to the sixth terminal of the RF chip for receiving the input signal provided by the RF chip at the transmission frequency, the second terminal of the amplifier/switch chip is coupled by a bandpass filter to the fifth terminal of the amplifier/switch chip and the switch couples the antenna terminal to the fifth terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the input signal provided by the RF chip at the transmission frequency and for providing the amplified signal to the antenna terminal for transmission; and

wherein when the received signals are either TDD transmitted and received signals or FDD transmitted and received signals, the switch couples the antenna terminal to the sixth terminal of the amplifier/switch chip and the sixth terminal of the amplifier/switch chip is coupled by a bandpass filter to the third terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the signal provided by the antenna at the reception frequency and for providing the signal amplified by the second amplifier to the fourth terminal of the RF chip.

7. A chip set according to claim 1, wherein the IF chip further includes

a first mixer having one input coupled to a sixth terminal of the IF chip, another input coupled to the output of the phase-locked oscillator and an output coupled to a seventh terminal of the IF chip;

a second mixer having one input coupled to an eighth terminal of the IF chip, another input coupled to a ninth input terminal and an output coupled to a tenth terminal of the IF chip;

a limiting amplifier having an input coupled to an eleventh terminal of the IF chip and an output coupled to a twelfth terminal of the IF chip; and

a sampling circuit having an input connected to a thirteenth terminal of the IF chip and an output connected to a fourteenth terminal of the IF chip;

wherein when the sixth terminal is coupled to the RF chip for receiving the received signal at the intermediate frequency, the second mixer down converts the frequency of the received signal from the intermediate frequency;

wherein when the down-converted received signal is QPSK modulated, the seventh terminal is coupled to the eighth terminal, the ninth terminal is coupled to a reference-frequency signal source, the tenth terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the thirteenth terminal, the IF chip is connected for sampling the down-converted received signal and for providing the sampled signal at the fourteenth terminal; and

wherein when the down-converted received signal is FSK modulated, the seventh terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the eighth terminal through a phase-shifting means and connected directly to the ninth terminal, the IF chip is connected for demodulating the down-converted received signal and for providing the demodulated signal at the tenth terminal.

8. A chip set according to claim 1, wherein the RF chip includes

a first mixer having one input coupled to a first terminal of the RF chip, another input coupled to a second terminal of the RF chip and an output coupled to a third terminal of the RF chip;

and

a second mixer having one input coupled to a fourth terminal of the RF chip, a another input coupled to a fifth terminal of the RF chip and an output coupled to a sixth terminal of the RF chip;

wherein when the transmitted and received signals are TDD transmitted and received signals, the first terminal of the RF chip is coupled to the IF chip for receiving the input signal provided by the IF chip at the intermediate frequency, the second terminal of the RF chip is coupled to a gain control circuit, the third terminal of the RF chip is coupled to the fourth terminal of the RF chip, and the fifth terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the transmission frequency and the intermediate frequency, the RF chip is connected for converting the frequency of the input signal provided by the IF chip to the transmission frequency and for providing the input signal at the transmission frequency at the sixth terminal of the RF chip; and

wherein when the transmitted and received signals are FDD transmitted and received signals, the first terminal of the RF chip is coupled to the IF chip for receiving the input signal provided by the IF chip at the intermediate frequency, the second terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the frequencies of the transmitted signal and the signal received by the antenna, the third terminal of the RF chip is coupled to the fourth terminal of the RF chip and the fifth terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the reception frequency and the intermediate frequency, the RF chip is connected for converting the frequency of the input signal provided by the IF chip to the transmission frequency and for providing the input signal at the transmission frequency at the sixth terminal of the RF chip.

9. A chip set according to claim 8, wherein the RF chip further includes

a third mixer having one input coupled to an seventh terminal of the RF chip, another input coupled to the fifth terminal of the RF chip and an output coupled to an eighth terminal of the RF chip;

wherein when the seventh terminal receives said received signal at the reception frequency, the fifth terminal of the RF chip is coupled to the source of the reference signal having a frequency equal to the difference between the transmission frequency and the intermediate frequency and the transmitted and received signals are TDD transmitted and received signals, the RF chip is connected for converting the frequency of the received signal from the reception frequency to the intermediate frequency and for providing the received signal at the intermediate frequency at the eighth terminal of the RF chip; and

wherein when the seventh terminal receives said received signal at the reception frequency, the fifth terminal of the RF chip is coupled to the source of the reference signal having a frequency equal to the difference between the reception frequency and the intermediate frequency and the transmitted and received signals are FDD transmitted and received signals, the RF chip is connected for converting the frequency of the received signal from the reception frequency to the intermediate frequency and for providing the received signal at the intermediate frequency at the eighth terminal of the RF chip.

10. A chip set according to claim 9, further comprising an amplifier/switch chip, including

a first amplifier having an input coupled to a first terminal of the amplifier/switch chip and an output coupled to a second terminal of the amplifier/switch chip;

a second amplifier having an input coupled to a third terminal of the amplifier/switch chip and an output coupled to a fourth terminal of the amplifier/switch chip;

an antenna terminal; and

a switch for coupling the antenna terminal to either a fifth terminal of the amplifier/switch chip or a sixth terminal of the amplifier/switch chip;

wherein when the transmitted and received signals are TDD transmitted and received signals, the first terminal of the amplifier/switch chip is coupled to the sixth terminal of the RF chip for receiving the input signal provided by the RF chip at the transmission frequency, the second terminal of the amplifier/switch chip is coupled by a low-pass filter to the fifth terminal of the amplifier/switch chip and the switch couples the antenna terminal to the fifth terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the input signal provided by the RF chip at the transmission frequency and for providing the amplified signal to the antenna terminal for transmission;

wherein when the transmitted and received signals are FDD transmitted and received signals, the first terminal of the amplifier/switch chip is coupled to the sixth terminal of the RF chip for receiving the input signal provided by the RF chip at the transmission frequency, the second terminal of the amplifier/switch chip is coupled by a bandpass filter to the fifth terminal of the amplifier/switch chip and the switch couples the antenna terminal to the fifth terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the input signal provided by the RF chip at the transmission frequency and for providing the amplified signal to the antenna terminal for transmission; and

wherein when the received signals are either TDD transmitted and received signals or FDD transmitted and received signals, the switch couples the antenna terminal to the sixth terminal of the amplifier/switch chip and the sixth terminal of the amplifier/switch chip is coupled by a bandpass filter to the third terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the signal provided by the antenna at the reception frequency and for providing the signal amplified by the second amplifier to the fourth terminal of the RF chip.

11. A chip set according to claim 1 in combination with a frequency synthesizer, wherein the IF chip includes

a digital-to-analog converter (DAC) for converting the digital input signal into the analog input signal, wherein the output of the DAC is coupled to a first terminal of the IF chip;

a phase-locked loop including a phase-locked oscillator, wherein the input of the phase-locked oscillator is coupled to a second terminal of the IF chip and the output of the phase-locked oscillator is coupled to a third terminal of the IF chip; and

a first mixer having one input coupled to the output of the phase-locked oscillator, a second input coupled to a fourth terminal of the IF chip and an output connected to a fifth terminal of the IF chip;

wherein the RF chip includes

a first mixer having one input coupled to a first terminal of the RF chip, another input coupled to a second terminal of the RF chip and an output coupled to a third terminal of the RF chip; and

a second mixer having one input coupled to a fourth terminal of the RF chip, a another input coupled to a fifth terminal of the RF chip and an output coupled to a sixth terminal of the RF chip;

wherein when the modulation of the digital input signal is QPSK and the first terminal is coupled to the fourth terminal for enabling the first mixer to mix the output of the phase-locked oscillator with the analog input signal, the IF chip is connected for providing to the fifth terminal the input signal at said intermediate frequency; and

wherein when the modulation of the digital input signal is FSK, the frequency synthesizer is tuned for providing an output signal at a reference frequency, the first terminal of the IF chip is connected to the frequency synthesizer for enabling the frequency synthesizer to be modulated with the analog input signal and the output of the frequency synthesizer is connected to the fifth terminal of the RF chip, the IF chip, the RF chip and the frequency synthesizer are connected for providing the modulated input signal at the transmission frequency from the output of the second mixer of the RF chip.

12. An intermediate frequency (IF) integrated circuit chip for use in a radio communication system in which a modulated digital input signal is processed for transmission and a signal received from an antenna is processed to provide a demodulated output signal, wherein the modulation of the digital input signal is either quadrature phase shift keying (QPSK) or frequency shift keying (FSK), wherein the chip is adapted for processing a digital input signal to convert the digital input signal into an analog input signal and to provide the input signal at an intermediate frequency and for processing a received signal at the intermediate frequency to down convert the frequency thereof and to provide an output signal from the down-converted received signal, the chip comprising

means for providing the input signal at said intermediate frequency when the modulation of the digital input signal is QPSK modulated and for providing the input signal at said intermediate frequency when the modulation of the digital input signal is FSK modulated;

means for sampling the down-converted received signal to provide said output signal when the down-converted received signal is QPSK modulated and for demodulating the down-converted received signal to provide said output signal when the down-converted received signal is FSK modulated; and

switches and terminals for enabling the IF chip to be connected for said processing by the IF chip of QPSK-modulated signals or to be connected for said processing by the IF chip of FSK-modulated signals.

13. An IF chip according to claim 12, comprising

a digital-to-analog converter (DAC) for converting the digital input signal into the analog input signal, wherein the output of the DAC is coupled to a first terminal of the IF chip;

a phase-locked loop including a phase-locked oscillator, wherein the input of the phase-locked oscillator is coupled to a second terminal of the IF chip and the output of the phase-locked oscillator is coupled to a third terminal of the IF chip; and

a first mixer having one input coupled to the output of the phase-locked oscillator, a second input coupled to a fourth terminal of the IF chip and an output connected to a fifth terminal of the IF chip;

wherein when the modulation of the digital input signal is QPSK and the first terminal is coupled to the fourth terminal for enabling the first mixer to mix the output of the phase-locked oscillator with the analog input signal, the IF chip is connected for providing to the fifth terminal the input signal at said intermediate frequency; and

wherein when the modulation of the digital input signal is FSK and the first terminal is connected to the second terminal for enabling the input of the phase-locked oscillator to be modulated with the analog input signal, the IF chip is connected for providing the input signal from the output of the phase-locked oscillator to the third terminal at said intermediate frequency.

14. An IF chip according to claim 13, further comprising

a second mixer having one input coupled to a sixth terminal of the IF chip, another input coupled to the output of the phase-locked oscillator and an output coupled to a seventh terminal of the IF chip;

a third mixer having one input coupled to an eighth terminal of the IF chip, another input coupled to a ninth input terminal and an output coupled to a tenth terminal of the IF chip;

a limiting amplifier having an input coupled to an eleventh terminal of the IF chip and an output coupled to a twelfth terminal of the IF chip; and

a sampling circuit having an input connected to a thirteenth terminal of the IF chip and an output connected to a fourteenth terminal of the IF chip;

wherein when the sixth terminal receives the received signal at the intermediate frequency, the second mixer down converts the frequency of the received signal from the intermediate frequency;

wherein when the down-converted received signal is QPSK modulated, the seventh terminal is coupled to the eighth terminal, the ninth terminal is coupled to a reference-frequency signal source, the tenth terminal is coupled 16 the eleventh terminal and the twelfth terminal is coupled to the thirteenth terminal, the IF chip is connected for sampling the down-converted received signal and for providing the sampled signal at the fourteenth terminal; and

wherein when the down-converted received signal is FSK modulated, the seventh terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the eighth terminal through a phase-shifting means and connected directly to the ninth terminal, the IF chip is connected for demodulating the down-converted received signal and for providing the demodulated signal at the tenth terminal.

15. An IF chip according to claim 12, further comprising

a first mixer having one input coupled to a sixth terminal of the IF chip, another input coupled to the output of the phase-locked oscillator and an output coupled to a seventh terminal of the IF chip;

a second mixer having one input coupled to an eighth terminal of the IF chip, another input coupled to a ninth input terminal and an output coupled to a tenth terminal of the IF chip;

a limiting amplifier having an input coupled to an eleventh terminal of the IF chip and an output coupled to a twelfth terminal of the IF chip; and

a sampling circuit having an input connected to a thirteenth terminal of the IF chip and an output connected to a fourteenth terminal of the IF chip;

wherein when the sixth terminal receives the received signal at the intermediate frequency, the second mixer down converts the frequency of the received signal from the intermediate frequency;

wherein when the down-converted received signal is QPSK modulated, the seventh terminal is coupled to the eighth terminal, the ninth terminal is coupled to a reference-frequency signal source, the tenth terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the thirteenth terminal, the IF chip is connected for sampling the down-converted received signal and for providing the sampled signal at the fourteenth terminal; and

wherein when the down-converted received signal is FSK modulated, the seventh terminal is coupled to the eleventh terminal and the twelfth terminal is coupled to the eighth terminal through a phase-shifting means and connected directly to the ninth terminal, the IF chip is connected for demodulating the down-converted received signal and for providing the demodulated signal at the tenth terminal.

16. A radio frequency (RF) integrated circuit chip set for use in a radio communication system in which a modulated digital input signal is processed for transmission and a signal received from an antenna is processed to provide a demodulated output signal, wherein the signal transmission and reception is by either time-division duplex (TDD) or frequency-division duplex (FDD), the chip comprising

means for processing an input signal provided at the intermediate frequency to up convert the frequency thereof to a transmission frequency and for processing a received signal provided at the reception frequency to down convert the frequency thereof to the intermediate frequency;

and

terminals for enabling the chip to be connected for said processing of TDD transmitted and received signals or to be connected for said processing of FDD transmitted and received signals.

17. An RF chip according to claim 16, comprising

a first mixer having one input coupled to a first terminal of the RF chip, another input coupled to a second terminal of the RF chip and an output coupled to a third terminal of the RF chip;

and

a second mixer having one input coupled to a fourth terminal of the RF chip, a another input coupled to a fifth terminal of the RF chip and an output coupled to a sixth terminal of the RF chip;

wherein when the transmitted and received signals are TDD transmitted and received signals, the first terminal of the RF chip receives an input signal at the intermediate frequency, the second terminal of the RF chip is coupled to a gain control circuit, the third terminal of the RF chip is coupled to the fourth terminal of the RF chip, and the fifth terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the transmission frequency and the intermediate frequency, the RF chip is connected for converting the frequency of the input signal to the transmission frequency and for providing the input signal at the transmission frequency at the sixth terminal of the RF chip; and

wherein when the transmitted and received signals are FDD transmitted and received signals, the first terminal of the RF chip receives an input signal at the intermediate frequency, the second terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the frequencies of the transmitted signal and the signal received by the antenna, the third terminal of the RF chip is coupled to the fourth terminal of the RF chip and the fifth terminal of the RF chip is coupled to a source of a reference signal having a frequency equal to the difference between the reception frequency and the intermediate frequency, the RF chip is connected for converting the frequency of the input signal provided at the intermediate frequency to the transmission frequency and for providing the input signal at the transmission frequency at the sixth terminal of the RF chip.

18. An RF chip according to claim 17, further comprising

a third mixer having one input coupled to an seventh terminal of the RF chip, another input coupled to the fifth terminal of the RF chip and an output coupled to an eighth terminal of the RF chip;

wherein when the seventh terminal receives said received signal at the reception frequency, the fifth terminal of the RF chip is coupled to the source of the reference signal having a frequency equal to the difference between the transmission frequency and the intermediate frequency and the transmitted and received signals are TDD transmitted and received signals, the RF chip is connected for converting the frequency of the received signal from the reception frequency to the intermediate frequency and for providing the received signal at the intermediate frequency at the eighth terminal of the RF chip; and

wherein when the seventh terminal receives said received signal at the reception frequency, the fifth terminal of the RF chip is coupled to the source of the reference signal having a frequency equal to the difference between the reception frequency and the intermediate frequency and the transmitted and received signals are FDD transmitted and received signals, the RF chip is connected for converting the frequency of the received signal from the reception frequency to the intermediate frequency and for providing the received signal at the intermediate frequency at the eighth terminal of the RF chip.

19. A chip set according to claim 18, in combination with an amplifier/switch chip that comprises

a first amplifier having an input coupled to a first terminal of the amplifier/switch chip and an output coupled to a second terminal of the amplifier/switch chip;

a second amplifier having an input coupled to a third terminal of the amplifier/switch chip and an output coupled to a fourth terminal of the amplifier/switch chip;

an antenna terminal; and

a switch for coupling the antenna terminal to either a fifth terminal of the amplifier/switch chip or a sixth terminal of the amplifier/switch chip;

wherein when the transmitted and received signals are TDD transmitted and received signals, the first terminal of the amplifier/switch chip is coupled to the sixth terminal of the RF chip for receiving the input signal provided by the RF chip at the transmission frequency, the second terminal of the amplifier/switch chip is coupled by a low-pass filter to the fifth terminal of the amplifier/switch chip and the switch couples the antenna terminal to the fifth terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the input signal provided by the RF chip at the transmission frequency and for providing the amplified signal to the antenna terminal for transmission;

wherein when the transmitted and received signals are FDD transmitted and received signals, the first terminal of the amplifier/switch chip is coupled to the sixth terminal of the RF chip for receiving the input signal provided by the RF chip at the transmission frequency, the second terminal of the amplifier/switch chip is coupled by a bandpass filter to the fifth terminal of the amplifier/switch chip and the switch couples the antenna terminal to the fifth terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the input signal provided by the RF chip at the transmission frequency and for providing the amplified signal to the antenna terminal for transmission; and

wherein when the received signals are either TDD transmitted and received signals or FDD transmitted and received signals, the switch couples the antenna terminal to the sixth terminal of the amplifier/switch chip and the sixth terminal of the amplifier/switch chip is coupled by a bandpass filter to the third terminal of the amplifier/switch chip, the amplifier/switch chip is connected for amplifying the signal provided by the antenna at the reception frequency and for providing the signal amplified by the second amplifier to the fourth terminal of the RF chip.