Generation and use of LDCs in wireless communication systems

A method for generating at least a partially optimized Linear Dispersion Code (LDC) for use in a Multiple-Input Multiple-Output (MIMO) communication system in which M transmit antennas are used to transmit a codeword over T time slots, each codeword encoding Q constellation symbols, wherein M, T and Q are real numbers, the method comprising:

• generating an initial matrix comprising 2Q columns and a predefined number M of rows;
• generating a population of different individual matrices from the initial matrix;
• deriving a respective second matrix comprising 2Q columns and M rows from each individual matrix;
• generating a set of 2Q LDCs comprising a respective set of LDC dispersion matrices from each second matrix, each LDC dispersion matrix comprising dimensions T×M;
• evaluating each LDC according to at least one criterion;
• selecting one of the LDCs as the at least partially optimized LDC according to the results of the evaluation;
• encoding data with the selected LDC;
• and
• transmitting the encoded data.

A communication method for transmitting data in a plurality of codewords from a plurality of transmit antennas, each codeword encoding a plurality of constellation symbols and each codeword being transmitted over a plurality of time slots, the method comprising:

• generating a plurality of Linear Dispersion Codes (LDCs) comprising a respective set of LDC dispersion matrices and corresponding to a different respective combination of T, M and Q values, wherein T, M and Q are real numbers;
• storing the plurality of LDCs in a memory means;
• determining a number M1 of transmit antennas in the plurality of transmit antennas;
• determining a number Q1 of constellation symbols in the plurality of constellation symbols;
• determining a number T1 of timeslots in the plurality of time slots;
• selecting from the memory means an LDC corresponding to T, M and Q values equal to T1, M1 and Q1, respectively, wherein T1, M1 and Q1 are real numbers;
• using the selected LDC to encode data into the plurality of codewords;
• and
• transmitting the codewords from the M1 transmit antennas.

A communication method for transmitting data in a plurality of codewords from M transmit antennas, each codeword encoding Q constellation symbols and each codeword being transmitted over T time slots, the method comprising:

• generating an initial matrix comprising 2Q columns and a predefined number M of rows;
• deriving a respective second matrix comprising 2Q columns and m rows from each first matrix;
• generating a set of 2Q Linear Dispersion Codes (LDCs) from each of the second matrices, the LDCs comprising a respective set of LDC dispersion matrices, each LDC dispersion matrix comprising dimensions T×M, wherein M, T and Q are real numbers;
• determining a performance of the plurality of different LDCs according to at least one criterion;
• selecting one of the LDCs according to its performance;
• using the selected LDC to encode data into the plurality of codewords;
• and
• transmitting the codewords from the transmit antennas.