Parallel interference cancellation receiver for multiuser detection of CDMA signals

An interference canceller for use in a receiver that separates received communication signals (r) from a plurality of transmitters over a CDMA interface into a plurality of desired signals (d(k)), the interference canceller comprising:

• a channel estimation processor for receiving the communication signals (r) producing individual impulse response estimates (A) for the plurality of desired signals (d(k)), said impulse response estimates coupled to a data estimation and interference canceller, said channel estimation processor further comprises:
• a channel estimator coupled to the communication signals (r) for outputting channel impulse response estimates (h(k)) for the plurality of desired signals (d(k)), said channel estimator coupled to a system response matrix assembler;
• said system response matrix assembler outputting system response matrices (A(n)(k)) for the plurality of desired signals (d(k));
• and
• said system response matrices (A(n)(k)) assembled into a total system response matrix (A) output;
• and
• said data estimation and interference canceller receiving the communication signals (r) and said impulse response estimates (A) and outputting the plurality of desired signals (d(k)), said data estimation and interference canceller further comprises:
• a matched-filter coupled to the communication signals (r) and said channel estimation processor output (A) for outputting estimates of the desired signals with selective signals (y) to a first input of a summer;
• said summer having an output (z(m)) coupled to a direct interference canceller;
• said direct interference canceller outputting scaled estimates of the desired signals with selective signals (d(m)) of the plurality of desired signals (d(k)) to an input of an iteration counter;
• said iteration counter having a first output coupled to a feedback interference processor;
• said feedback interference processor outputting interference estimates (c(m)) of the selective signals to a second input of said summer;
• and
• said interference estimates (c(m)) subtracted from said matched-filter output (y) for m iterations by said iteration counter whereby said iteration counter outputs said estimates of the desired signals (d(m)) as the plurality of desired signals (d(k)) absent said selective signals through a second output.