Antenna selection and training using a spatial spreading matrix for use in a wireless mimo communication system

A method of antenna selection within a communication system having a first transceiver device having a plurality of transmission antennas and a second transceiver device having a plurality of receiving antennas, the method comprising:

• defining a spatial spreading matrix used to distribute a number of encoded spatial data streams to a number of transmission chains for transmitting the encoded spatial data streams as a first set of columns in a full-dimensional channel spatial spreading matrix, wherein the full-dimensional channel spatial spreading matrix has components associated with a row dimension having a number of rows equal to the number of transmission chains and a column dimension having a number of columns equal to the number of transmission chains, wherein the number of columns in the first set of column in the full-dimensional channel spatial spreading matrix equals the number encoded spatial data streams to be transmitted;
• and
• selecting one or more of the plurality of receiving antennas to be used to receive one or more encoded spatial data streams transmitted through a channel estimation matrix between the first transceiver device and the second transceiver device and to be received via a number of receiving chains, wherein the number of encoded spatial data streams is different than the number of transmitting chains used to transmit the encoded spatial data streams and wherein the number of receiving chains is less than the number of receiving antennas,
• wherein selecting one or more of the plurality of receiving antennas comprises accounting for the defined spatial spreading matrix.

A method of antenna selection training for a transceiver device having a plurality of antennas, wherein the antennas are selected for a data transmission of one or more encoded spatial data streams via a channel estimation matrix having a number of transmitting and receiving chains between one or more transmission antennas and one or more receiving antennas, the method comprising:

• searching potential channel sub-matrices within a full-dimensional channel matrix corresponding to a full-dimensional description of the channel between a plurality of transmission antennas and a plurality of receiving antennas, wherein the full-dimensional channel matrix has components associated with a row dimension having a number of rows equal to the number of receiving antennas and a column dimension having a number of columns equal to the number of transmission antennas, and wherein each channel sub-matrix has components associated with a row dimension having a number of rows equal to the number of receiving chains to be used to receive the data and a column dimension having a number of columns equal to the number of transmitting chains to be used to transmit the data, wherein the number of encoded spatial data streams is less than the minimum of the number of transmission chains and the number of receiving chains, and the number of receiving chains is less than the number of receiving antennas and/or the number of transmitting chains is less than the number of transmission antennas;
• right-multiplying each potential channel sub-matrix with a spatial spreading matrix to form a corresponding channel sub-matrix having components associated with a row dimension having a number of rows equal to a number of receiving chains and a column dimension having a number of columns equal to the number of encoded spatial data streams to be transmitted, wherein the spatial spreading matrix has components associated with a row dimension having a number of rows equal to the number of transmission chains to be used to transmit the encoded spatial data streams and a column dimension having a number of columns equal to the number of encoded spatial data streams to be transmitted,
• selecting one of the channel sub-matrices based on an optimality criterion, wherein a channel estimation matrix used to transmit the data from the one or more transmission antennas to the one or more receiving antennas comprises the selected channel sub-matrix;
• and
• selecting the antennas corresponding to the selected channel sub-matrix.

An apparatus within a transmission system having two or more antennas comprising:

• a spatial spreading calculation unit to produce a spatial spreading matrix to distribute one or more encoded spatial data streams among a number of chains within a chain-to-chain transmission through a channel matrix, wherein the number of encoded spatial data streams is less than the minimum of the number of transmission chains and the number of receiving chains, wherein the channel estimation matrix has components associated with a row dimension having a number of rows equal to a number of receiving chains and a column dimension having a number of columns equal to the number of encoded spatial data streams, and wherein the number of transmission chains and/or the number of receiving chains is less than the number of antennas;
• and
• a controller coupled to the spatial spreading calculation unit to control the selection of the two or more antennas used in the chain-to-chain transmission using the spatial spreading matrix;
• wherein the spatial spreading matrix has components associated with a row dimension having a number of rows equal to the number of transmission chains used the transmission of the encoded spatial data streams and a column dimension having a number of columns equal to the number of encoded spatial data streams.