CDMA wireless system

A receiver for receiving data signals transmitted by multiple transmitters, each data signal having a data stream that is independent of the data streams of the other data signals, comprising:

• a plurality of antennas configured to receive the transmitted data signals;
• a signal processor configured to suppress signal interference in the signals, wherein the signal processor comprises:
• an interference suppression unit configured to perform interference suppression on the signals, wherein the interference suppression unit comprises:
• a plurality of finger interference suppression units configured to make preliminary decisions as to values of the data streams of the respective signals;
• and
• a combiner configured to combine the preliminary decisions from the plurality of finger interference suppression units;
• a tentative decision unit configured to generate an estimate of each signal output by the interference suppression unit;
• and
• a soft decision unit configured to make a soft decision as to a value of the data streams in each signal output by the tentative decision unit;
• a channel decoder coupled to the signal processor and configured to decode the signals;
• and
• a combiner configured to combine the output of the channel decoder into a single data stream.

A receiver for receiving data signals transmitted by multiple transmitters, each data signal having a data stream that is independent of the data streams of the other data signals, comprising:

• a plurality of antennas configured to receive the transmitted data signals;
• a signal processor configured to suppress signal interference in the signals, wherein the signal processor comprises:
• a plurality of finger interference suppression units configured to make preliminary decisions as to values of the data streams of each of the respective signals;
• first and second combiners configured to combine the preliminary decisions from the plurality of finger interference suppression units;
• a tentative decision unit configured to generate an estimate of each signal output by the interference suppression unit;
• and
• a soft decision unit configured make a soft decision as to the value of the data streams in each signal output by the tentative decision unit;
• a channel decoder coupled to the signal processor and configured to decode the signals;
• and
• a combiner configured to combine the output of the channel decoder into a single data stream.

A receiver for receiving data signals transmitted by multiple transmitters, each data signal having a data stream that is independent of the data streams of the other data signals, comprising:

• a first and second antenna configured to receive respective first and second transmitted data signals;
• a first filter configured to filter the first signal and a second filter configured to filter the second signal;
• a first multiplier configured to despread the first filtered signal and a second multiplier configured to despread the second filtered signal;
• a signal processor configured to suppress signal interference in the first and second despread signals, wherein the signal processor comprises:
• an interference suppression unit configured to perform interference suppression on the first and second despread signals;
• a first tentative decision unit configured to generate an estimate of the first signal output by the interference suppression unit, and a second tentative decision unit configured to generate an estimate of the second signal output by the interference suppression unit;
• and
• a soft decision unit configured to make a soft decision as to values of the data streams in the first and second signals output by the first and second tentative decision units;
• a first and second channel decoders coupled to the signal processor and configured to decode the first and second despread signals, respectively;
• and
• a combiner configured to combine the outputs of the first and second channel decoders into a single data stream.

A receiver for receiving data signals transmitted by multiple transmitters, each data signal having a data stream that is independent of the data streams of the other data signals, comprising:

• a first and second antenna configured to receive respective first and second transmitted data signals;
• a first filter configured to filter the first signal and a second filter configured to filter the second signal;
• a first multiplier configured to despread the first filtered signal and a second multiplier configured to despread the second filtered signal;
• a signal processor configured to suppress signal interference in the first and second despread signals, wherein the signal processor comprises:
• a plurality of finger interference suppression units configured to receive respective signals from the first and second multipliers and make preliminary decisions as to values of the data streams of each of the first and second filtered signals;
• first and second combiners configured to combine the preliminary decisions from the plurality of finger interference suppression units;
• a first tentative decision unit configured to generate an estimate of the first signal output by the first combiner, and a second tentative decision block configured to generate an estimate of the second signal output by the second combiner;
• and
• an interference cancellation and soft decision unit configured to make soft decisions as to values of the data streams in the first and second signals output by the first and second tentative decision units;
• a first and second channel decoders coupled to the signal processor and configured to decode the first and second despread signals, respectively;
• and
• a combiner configured to combine the outputs of the first and second channel decoders into a single data stream.

A method for receiving data signals transmitted by multiple transmitters, each data signal having a data stream that is independent of the data stream of the other data signals, comprising:

• receiving a first data signal at a first antenna and a second data signal at a second antenna;
• filtering the first and second received signals;
• despreading each filtered signal;
• suppressing signal interference in each despread signal, wherein the suppressing step comprises:
• making a preliminary decision on the value of the data steam of each despread signal;
• combining the preliminary decisions;
• calculating an estimate for each despread signal;
• calculating the reliability of each estimate;
• and
• making a soft decision as to the value of the data streams of each received signal;
• decoding each signal interference suppressed signal;
• and
• assembling the decoded signals into a single serial data stream.

A method for receiving data signals transmitted by multiple transmitters, each data signal having a data stream that is independent of the data stream of the other data signals, comprising:

• receiving a first data signal at a first antenna and a second data signal at a second antenna;
• filtering the first and second received signals;
• despreading each filtered signal;
• suppressing signal interference in each despread signal, wherein the suppressing step comprises:
• calculating a first estimate of the first despread signal and a second estimate of the second despread signal;
• calculating the reliability of each estimate;
• multiplying each estimate by channel information about the channel from its transmitter to the receiver;
• determining the difference between the first received signal and the contribution to the first received signal arising from the first estimate and the channel information;
• determining the difference between the second received signal and the contribution to the second received signal arising from the second estimate and the channel information;
• creating a new estimate for each of the first and second despread signals;
• calculating the reliability for each new estimate;
• summing the reliability of the first new estimate with the reliability of the first estimate and summing the reliability of the second new estimate with the reliability of the second estimate;
• and
• comparing the results of the summing step and outputting one of the new estimates based on said comparing step;
• decoding each signal interference suppressed signal;
• and
• assembling the decoded signals into a single serial data stream.

A communication system for a data stream of digital information comprising:

• a plurality of transmitters each configured to split the data stream into a plurality of independent data streams each having data that is independent of the data in the other of the split data streams and to transmit the independent data streams;
• and
• a receiver comprising:
• a plurality of antennas configured to receive the transmitted data signals;
• a signal processor configured to suppress signal interference in the signals, wherein the signal processor comprises:
• an interference suppression unit configured to perform interference suppression on the first and second despread signals;
• a first tentative decision unit configured to generate an estimate of the first signal output by the interference suppression unit, and a second tentative decision unit configured to generate an estimate of the second signal output by the interference suppression unit;
• and
• a soft decision unit configured to make a soft decision as to values of the data streams in the first and second signals output by the first and second tentative decision units;
• first and second channel decoders coupled to the signal processor and configured to decode the signals;
• and
• a combiner configured to combine the outputs of the first and second channel decoders into a single data stream.

A method for iterative interference suppression comprising:

• receiving first and second despread signals;
• calculating a first estimate of the first despread signal and a second estimate of the second despread signal;
• calculating the reliability of each estimate;
• multiplying each estimate by channel information;
• determining the difference between the first received signal and the contribution to the first received signal arising from the first estimate and the channel information;
• determining the difference between the second received signal and the contribution to the second received signal arising from the second estimate and the channel information;
• creating a new estimate for each of the first and second despread signals;
• calculating the reliability for each new estimate;
• summing the reliability of the first new estimate with the reliability of the first estimate and summing the reliability of the second new estimate with the reliability of the second estimate;
• and
• comparing the results of the summing steps and outputting one of the new estimates based on the comparison result.