Advanced signal processors for interference cancellation in baseband receivers
An interference canceller comprises a composite interference vector (CIV) generator configured to produce a CIV by combining soft and/or hard estimates of interference, an interference-cancelling operator configured for generating a soft projection operator, and a soft-projection canceller configured for performing a soft projection of the received baseband signal to output an interference-cancelled signal. Weights used in the soft-projection operator are selected to maximize a post-processing SINR.
1. A method for cancelling interference from a received baseband signal, the method comprising:
generating at least one composite interference vector (CIV) by combining estimates from interfering subchannels, wherein the estimates are derived from at least one of a Rake receiver, an equalizer, a receiver employing receive diversity, a receiver employing transmit diversity combining, or a receiver employing space-time decoding;
generating a soft-cancellation operator; and
performing a soft cancellation of the received baseband signal to output an interference-cancelled signal.
2. The method of claim 1 , wherein:
the generating at least one CIV comprises deriving the estimates from the Rake receiver; and
each finger of the Rake receiver is matched to at least one of a time delay or a base station spreading code.
3. The method of claim 1 , wherein the generating at least one CIV further comprises generating at least one or more soft estimates corresponding to interfering user subchannels from each base station tracked by a cellular handset.
4. The method of claim 1 , wherein the soft cancellation operator comprises a soft-projection matrix generator or an interference-cancelling operator configured for selecting a soft weight that increases a post-processing signal-to-interference-plus-noise-ratio (SINR).
5. The method of claim 1 , wherein the generating the at least one CIV comprises deriving the estimates from at least one of a Rake receiver, an equalizer, a receiver employing receive diversity, a receiver employing transmit diversity combining, or a receiver employing space-time decoding.
6. The method of claim 1 , wherein the performing the soft cancellation further comprises coupling the interference-cancelled signal to at least one of a combiner or a Rake receiver.
7. An apparatus for cancelling interference from a received baseband signal, wherein the apparatus is configured to perform operations comprising:
generating at least one composite interference vector (CIV) by combining estimates from interfering subchannels, wherein the estimates are derived from at least one of a Rake receiver, an equalizer, a receiver employing receive diversity, a receiver employing transmit diversity combining, or a receiver employing space-time decoding;
generating a soft-cancellation operator; and
performing a soft cancellation of the received baseband signal to output an interference-cancelled signal.
8. The apparatus of claim 7 , wherein the apparatus is configured to perform operations comprising:
the generating at least one CIV comprises deriving the estimates from the Rake receiver.
9. The apparatus of claim 8 , wherein each finger of the Rake receiver is matched to at least one of a time delay or a base station spreading code.
10. The apparatus of claim 7 , wherein the apparatus is configured to perform operations comprising:
the generating at least one CIV further comprises generating at least one or more soft estimates corresponding to interfering user subchannels from each base station tracked by a cellular handset.
11. The apparatus of claim 7 , wherein the soft cancellation operator comprises a soft-projection matrix generator or an interference-cancelling operator configured for selecting a soft weight that increases a post-processing signal-to-interference-plus-noise-ratio (SINR).
12. The apparatus of claim 7 , wherein the apparatus is configured to perform operations comprising:
wherein the generating the at least one CIV comprises deriving the estimates from at least one of a Rake receiver, an equalizer, a receiver employing receive diversity, a receiver employing transmit diversity combining, or a receiver employing space-time decoding.
13. The apparatus of claim 7 , wherein the apparatus is configured to perform operations comprising:
wherein the performing the soft cancellation further comprises coupling the interference-cancelled signal to at least one of a combiner or a Rake receiver.
14. At least one non-transitory computer-readable medium including software that, when executed by at least one processor, causes operations comprising:
generating at least one composite interference vector (CIV) by combining estimates from interfering subchannels, wherein the estimates are derived from at least one of a Rake receiver, an equalizer, a receiver employing receive diversity, a receiver employing transmit diversity combining, or a receiver employing space-time decoding;
generating a soft-cancellation operator; and
performing a soft cancellation of from a received baseband signal to output an interference-cancelled signal.
15. The at least one non-transitory computer-readable medium of claim 14 that includes software that, when executed by the at least one processor, causes further operations comprising:
the generating at least one CIV comprises deriving the estimates from the Rake receiver.
16. The at least one non-transitory computer-readable medium of claim 15 , wherein each finger of the Rake receiver is matched to at least one of a time delay or a base station spreading code.
17. The at least one non-transitory computer-readable medium of claim 14 that includes software that, when executed by the at least one processor, causes further operations comprising:
the generating at least one CIV further comprises generating at least one or more soft estimates corresponding to interfering user subchannels from each base station tracked by a cellular handset.
18. The at least one non-transitory computer-readable medium of claim 14 , wherein the soft cancellation operator comprises a soft-projection matrix generator or an interference-cancelling operator configured for selecting a soft weight that increases a post-processing signal-to-interference-plus-noise-ratio (SINR).
19. The at least one non-transitory computer-readable medium of claim 14 that includes software that, when executed by the at least one processor, causes further operations comprising:
wherein the generating the at least one CIV comprises deriving the estimates from at least one of a Rake receiver, an equalizer, a receiver employing receive diversity, a receiver employing transmit diversity combining, or a receiver employing space-time decoding.
20. The at least one non-transitory computer-readable medium of claim 14 that includes software that, when executed by the at least one processor, causes further operations comprising:
wherein the performing the soft cancellation further comprises coupling the interference-cancelled signal to at least one of a combiner or a Rake receiver.