Apparatus and method for detecting communications from multiple sources

An apparatus for detecting sequences of digitally modulated symbols transmitted by multiple sources, the apparatus comprising a detector operable to:

• determine a real-domain representation that separately treats in-phase and quadrature components of a received vector, channel gains, and a transmitted vector transmitted by the multiple sources;
• process the real-domain representation to obtain a triangular matrix;
• and
• perform at least one of:
• (i) hard decision detection of a transmitted sequence and demapping of corresponding bits based on a reduced complexity search of a number of transmit sequences, and (ii) generation of bit soft-output values based on the reduced complexity search of the number of transmit sequences, the reduced complexity search based on the triangular matrix.

A computer program embodied on a computer readable medium and operable to be executed by a processor, the computer program comprising computer readable program code for:

• determining a real-domain representation that separately treats in-phase and quadrature components of a received vector, channel gains, and a transmitted vector transmitted by multiple sources;
• processing the real-domain representation to obtain a triangular matrix;
• and
• performing at least one of:
• (i) hard decision detection of a transmitted sequence and demapping of corresponding bits based on a reduced complexity search of a number of transmit sequences, and (ii) generation of bit soft-output values based on the reduced complexity search of the number of transmit sequences, the reduced complexity search based on the triangular matrix.