Method and apparatus for smart adaptive dynamic range multiuser detection radio receiver

Patent metadata

Field	Value
Publication number	US-9998199-B2
Application number	US-201314648049-A
Country	US
Kind code	B2
Filing date	Jun 21, 2013
Priority date	Mar 14, 2013
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

A receiver includes multi-user detection (MUD) functionality and a cognitive engine. The receiver may also be coupled to multiple antennas and have analog beamforming capability. The cognitive engine is operative for selecting a beam or beams associated with the multiple antennas to enable successful demodulation by the MUD. The receiver has application in multiple access channels and in other communication scenarios.

First claim

The invention claimed is:

1. A communication device for use in a multi-signal wireless environment having a signal of interest and one or more interfering signals in a common frequency band wherein the signal of interest has a received power level which is lower than the received power level of at least one of the one or more interfering signals, the device comprising:
multiple antennas, each of the antennas having an antenna port for connection to respective ones of the multiple antennas;
at least one analog beamformer to form different receive beams for the multiple antennas, each receive beam to receive a composite analog signal comprised of the signal of interest and the one or more interfering signals and wherein relative received power levels between the lower power signal of interest and each of the one or more higher power interfering signals is different for each receive beam;
a multi-user detector (MUD) capable of demodulating a signal of interest within a composite signal comprising the signal of interest and at least one of the one or more higher power interfering signals; and
a cognitive engine configured to select one or more receive beams that will result in a received power difference between the lower power signal of interest and the one or more other higher power interfering signals that are delivered to the MUD, wherein the one or more receive beams are selected to optimize demodulation of the signal of interest in the MUD such that the MUD is able to process the signal of interest to produce a bit stream having a level of errors correctable by an error correction decoder in a receiver coupled to the MUD.

2. The communication device of claim 1 wherein the one or more receive beams are selected to optimize detection and demodulation of the signal of interest in the MUD while providing a received power difference between the lower power signal of interest and each of the one or more higher power interfering signals that is above a minimal power difference threshold required by a version of the MUD algorithm implemented in the receiver and wherein the communication device further comprises:
a parameter estimator configured to estimate signal parameters and to compute one or more signal metrics for each signal within each of a plurality of receive beams generated by the at least one analog beamformer, wherein the cognitive engine is configured to select the one or more receive beams based, at least in part, on the signal metrics computed by the parameter estimator.

3. The communication device of claim 2 , wherein:
the one or more signal metrics computed by the parameter estimator includes a signal to noise ratio (SNR), wherein noise does not include the signal of interest and the one or more higher power interfering signals.

4. The communication device of claim 2 , wherein:
the parameter estimator is configured to estimate one or more low quality signal parameters associated with signals received within receive beams generated by the at least one analog beamformer; and
the cognitive engine is configured to select the one or more receive beams based, at least in part, on the low quality signal parameter estimates.

5. The communication device of claim 4 , wherein:
the cognitive engine includes a beam grading unit to provide grades for beams or beam combinations that are indicative of the beams or beam combinations respective advantage provided to the MUD demodulator for the specific signals of interest; and
the parameter estimator includes an optimization unit coupled to receive the beam grades from the beam grading unit and to use the grades to optimize the choice of beams for which low quality signal parameter estimates are generated in a recursive fashion.

6. The communication device of claim 4 , wherein:
the one or more low quality signal parameters estimated by the parameter estimator include at least one of: a number of coexisting signals, a baud rate for each signal, baud timing for each signal, carrier offset for each signal, error correction coding rate for each signal, and modulation scheme for each signal.

7. The communication device of claim 2 , wherein:
the at least one analog beamformer includes multiple combiners that are each configured to linearly combine signals received at the multiple antennas in a different manner, wherein an output of each of the multiple combiners is coupled to an input of the parameter estimator.

8. The communication device of claim 7 , further comprising:
a beam selector switch coupled to outputs of the multiple combiners to select, under control of the cognitive engine, one or more of the beams generated by the multiple combiners for further receiver processing.

9. The communication device of claim 2 , wherein:
the at least one analog beamformer includes a linear combiner having configurable combining weights, the linear combiner having an output that is coupled to an input of the parameter estimator, wherein the linear combiner is capable of achieving a variety of different receive beams if the combining weights are varied.

10. The communication device of claim 9 , further comprising:
a weight generation unit to generate weights for the linear combiner under control of the cognitive engine to achieve different receive beams.

11. The communication device of claim 10 , further comprising:
a receive chain having at least one of an automatic gain controller or an analog to digital converter, wherein the parameter estimator includes a gradient calculator to determine gradients for updating the linear combiner weights based upon each of the differences in received power of the signal of interest and the received power of each of the one or more higher power interfering signals at the output of the at least one of an automatic gain controller or an analog to digital converter, the parameter estimator configured to deliver the gradients to the cognitive engine for use in updating the weights of the linear combiner.

12. The communication device of claim 2 , wherein:
the parameter estimator includes a direction of arrival estimator to estimate angles of arrival of signals within the plurality of receive beams.

13. The communication device of claim 12 , wherein:
the parameter estimator includes a beam power difference estimator to estimate the differences in received powers between the signal of interest and higher power interfering signals in each received beam using the direction of arrival information generated by the direction of arrival estimator and known beam patterns associated with the different receive beams; and
the cognitive engine is configured to select the one or more receive beams based, at least in part, on the estimated received power difference of the signal of interest and each of the one or more higher power interfering signals being received in each beam.

14. The communication device of claim 1 , wherein:
the cognitive engine is configured to deliver information identifying a selected beam or beams to the MUD.

15. The communication device of claim 1 , wherein the cognitive engine includes:
an operating point determination unit to identify an operating point of the communication device based, at least in part, on powers and rates associated with signals received through a selected beam; and
a beam grading unit to determine which one or more of the available receive beams or beam combinations is feasible for use at the operating point and, if so, to determine a grade for each beam or beam combination.

16. The communication device of claim 15 , wherein the cognitive engine further includes:
an ordered

Assignees

• Massachusetts Inst Technology

Inventors

• Learned Rachel E
• Fiore Paul David

Classifications

• H04K3/228

  Elimination in the received signal of jamming or of data corrupted by jamming (interference suppression in receivers H04B1/10) · CPC title

• H04K2203/32

  including a particular configuration of antennas · CPC title

• H04B7/086 Primary

  using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming · CPC title

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title