Multi-channel digital transceiver and method

• US 5,818,883 A
• Filed: 07/23/1996
• Issued: 10/06/1998
• Est. Priority Date: 12/29/1994
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Laird, Kevin Michael, Kobrinetz, Tony, Smith, Paul Fielding, Luz, Yuda Yehuda, Smith, John M., Rottinghaus, Alan P., Pinckley, Danny Thomas, Lurey, Daniel Morris, Rader, Shelia Marie, Bailey, Donald E., Elder, Robert C.
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US08/685,123
• Time in Patent Office: 805 Days
• Field of Search: 375/260, 375/267, 375/347, 375/344-345, 455/132-134, 455/275, 455/276.1, 455/277.1, 455/277.2
• US Class Current: 375/347
• CPC Class Codes: H01Q 1/246 specially adapted for base stations
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H03B 28/00 Generation of oscillations by methods not covered by groups H03B5/00 - H03B27/00, including modification of the waveform to produce sinusoidal oscillations analogue function generators for performing computing operations G06G7/26; use of transformers for conversion of waveform in ac-ac converters H02M5/18
• CPC Class Codes: H03C 1/00 Amplitude modulation H03C5/00, H03C7/00 take precedence
• CPC Class Codes: H03C 3/00 Angle modulation H03C5/00, H03C7/00 take precedence
• CPC Class Codes: H03D 7/165 at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• CPC Class Codes: H04B 1/001 Channel filtering, i.e. selecting a frequency channel within the SDR system multiplexing of multicarrier modulation signals being represented by different frequencies H04L5/06; multiplexing of multicarrier modulation signals H04L5/023
• CPC Class Codes: H04B 1/0017 Digital filtering H04B1/001 takes precedence; digital filters per se H03H17/00
• CPC Class Codes: H04B 1/0021 Decimation, i.e. data rate reduction techniques H04B1/0025 takes precedence
• CPC Class Codes: H04B 1/0483 Transmitters with multiple parallel paths
• CPC Class Codes: H04B 1/16 Circuits
• CPC Class Codes: H04B 1/26 for superheterodyne receivers multiple frequency-changing H03D7/16
• CPC Class Codes: H04B 1/28 the receiver comprising at least one semiconductor device having three or more electrodes
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
• CPC Class Codes: H04B 1/40 Circuits
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/06 at the transmitting station
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0874 : using subgroups of receive antennas
• CPC Class Codes: H04B 7/18515 : Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/24 : for communication between two or more posts wireless communication networks H04W
• CPC Class Codes: H04L 1/06 : using space diversity
• CPC Class Codes: H04L 1/22 : using redundant apparatus to increase reliability
• CPC Class Codes: H04W 4/18 : Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 88/06 : adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A multi-channel digital transceiver (400) receives uplink radio frequency signals and converts these signals to digital intermediate frequency signals. Digital signal processing, including a digital converter module (426), is employed to select digital intermediate frequency signals received at a plurality of antennas (412) and to convert these signals to baseband signals. The baseband signals are processed to recover a communication channel therefrom. Downlink baseband signals are also processed and digital signal processing within the digital converter module (426) up converters and modulates the downlink baseband signals to digital intermediate frequency signals. The digital intermediate frequency signals are converted to analog radio frequency signals, amplified and radiated from transmit antennas (420).

Claims

1. A multi-channel digital receiver comprising:

a plurality of antennae for receiving radio frequency signals;

a plurality of radio frequency converters each coupled to one of the plurality of antennae and operable to convert the radio frequency signals to intermediate frequency signals;

a plurality of analog-to-digital converters coupled to each of the radio frequency converters for converting the intermediate frequency signals to digital signals;

a plurality of switched digital down converters coupled to the analog-to-digital converters and operable for coupling to receive one of the digital signals and converting the digital signal to a baseband intermediate frequency signal; and

a plurality of channel processors coupled to the plurality of switched digital down converters for recovering one of a plurality of communication channels contained within the baseband intermediate frequency signal, the plurality of channel processors being operable to select one of the plurality of digital down converters for coupling to one of the plurality of analog-to-digital converters.

2. The multi-channel digital receiver as in claim 1 wherein the switched digital down-converter is programmable.

3. The multi-channel digital receiver as in claim 1 wherein the switched digital down converter comprises a digital switch, a complex multiplier responsive to the digital switch, and a numerically controlled oscillator in communication with the complex multiplier.

4. The multi-channel digital receiver as in claim 1 wherein the switched digital down converter is programmable to select one of a plurality of decimation ratios for down converting the digital signals to a baseband intermediate frequency signal.

5. The multi-channel digital receiver as in claim 4 wherein the switched digital down converter is programmable to select one of the plurality of decimation ratios for down converting the digital signals to the baseband intermediate frequency signal under control of one of the plurality of channel processors.

6. The multi-channel digital receiver as in claim 1 wherein the switched digital down converter is programmable to select one of a plurality of channel bandwidths defining a communication channel of the plurality of communication channels.

7. The multi-channel digital receiver as in claim 6 wherein the switched digital down converter is programmable under control of one of the plurality of channel processors.

8. The multi-channel digital receiver as in claim 1 wherein the switched digital down converter is coupled to the plurality of channel processors via an interface media.

9. The multi-channel digital receiver as in claim 8 wherein the interface media comprises one of a microwave link, a fiber optic link, and a time domain multiplex link.

10. The multi-channel digital receiver as in claim 3 wherein each of the plurality of switched digital down converters further comprises a plurality of decimator filters responsive to the complex multiplier.

11. An apparatus for receiving radio frequency communications comprising:

a plurality of antennae for receiving radio frequency signals;

means for converting the radio frequency signals to intermediate frequency signals;

means for converting the intermediate frequency signals to digital signals;

means for digitally down converting one of the digital signals to a baseband intermediate frequency signal, the means for digitally down converting comprises a plurality of digital down converters, each being coupled to the means for converting the intermediate frequency signals to digital signals and including means for coupling to one of the digital signals; and

means for processing the baseband intermediate frequency signal operable to select one of the plurality of digital down converters for receiving one of the digital signals from the means for converting the intermediate frequency signals, for receiving a baseband intermediate frequency signal from the means for digitally down converting, and to recover a communication channel contained therein.

12. The apparatus as in claim 11 wherein the means for digitally down converting comprises a plurality of digital down converters, each of the plurality of digital down converters being coupled to the means for converting and the means for processing.

13. The apparatus as in claim 12 wherein the means for processing is operable to select one of the plurality of digital down converters for receiving a baseband intermediate frequency signal therefrom.

14. The apparatus as in claim 11 wherein the means for digitally down converting one of the digital signals to the baseband intermediate frequency signal is programmable.

15. The apparatus as in claim 14 wherein the means for digitally down converting one of the digital signals to the baseband intermediate frequency signal is programmable at the direction of the means for processing.

16. The apparatus as in claim 11 wherein the means for digitally down converting is programmable to select one of a plurality of decimation ratios for down converting the digital signals to a baseband intermediate frequency signal.

17. The apparatus as in claim 16 wherein the means for digitally down converting is programmable to select one of the plurality of decimation ratios for down converting the digital signals to the baseband intermediate frequency signal at the direction of the means for processing.

18. The apparatus as in claim 11 wherein the means for digitally down converting is programmable to select one of a plurality of channel bandwidths defining a communication channel of the plurality of communication channels.

19. The apparatus as in claim 18 wherein the means for digitally down converting is programmable at the direction of the processing means.

20. The apparatus as in claim 11 further comprising means for interfacing the means for digitally down converting with the processing means.

21. The apparatus as in claim 20 wherein the means for interfacing comprises a microwave link.

22. The apparatus as in claim 20 wherein the means for interfacing comprises a fiber optic link.

23. The apparatus as in claim 20 wherein the means for interfacing comprises a time domain multiplex link.

24. A method of receiving radio frequency communications comprising the steps of:

receiving radio frequency signals at a plurality of antennae;

converting the radio frequency signals to intermediate frequency signals;

converting the intermediate frequency signals to digital signals;

digitally down converting one of the digital signals to a baseband intermediate frequency signal;

processing the baseband intermediate frequency signal to recover one of a plurality of communication channels contained therein; and

selecting one of a plurality of digital down converters for receiving one of the digital signals.

25. The method as in claim 24 wherein the step of selecting comprises switching between the digital signals.

26. The method as in claim 24 wherein the step of digitally down converting comprises selecting one of the plurality of digital down converters and digitally down converting one of the digital signals to a baseband intermediate frequency signal.

27. The method as in claim 24 wherein the step of digitally down converting comprises decimating one of the digital signals at one of a plurality of decimation ratios.

28. The method as in claim 24 wherein the step of digitally down converting comprises selecting one of a plurality of channel bandwidths which defines a communication channel.

29. The method as in claim 24 further comprising the step of communicating the baseband intermediate frequency signal via a microwave link.

30. The method as in claim 24 further comprising the step of communicating the baseband intermediate frequency signal via a fiber optic.

31. The method as in claim 24 further comprising the step of communicating the baseband intermediate frequency signal via a time domain multiplex line.