Apparatus and method for selection of precoding matrix

An apparatus capable of precoding matrix selection, the apparatus comprising:

• a combining unit configured to determine whether a second signal vector includes an error by combining a first signal vector and the second signal vector that is received from a transmitter;
• and
• a calculation unit configured to calculate an effective signal-to-noise ratio for selecting a precoding matrix to be used for retransmission of the second signal vector to the transmitter in accordance with the combining of the first signal vector and the second signal vector, and configured to select the precoding matrix based on the calculated effective signal-to-noise ratio,
• wherein the calculation unit is configured to calculate the effective signal-to-noise ratio by calculating post detection signal noise ratio vectors from an effective channel matrix in accordance with the combining of the first signal vector and the second signal vector, and calculating the effective signal-to-noise ratio by aggregating the calculated post detection signal-to-noise ratio vectors.

A communication terminal capable of communicating in a wireless communication network, the communication terminal comprising:

• a precoding matrix selecting apparatus configured to select a precoding matrix, the precoding matrix selecting apparatus comprising:
• a combining unit configured to determine whether a second signal vector includes an error by combining a first signal vector and the second signal vector that is received from a transmitter;
• and
• a calculation unit configured to calculate an effective signal-to-noise ratio for selecting the precoding matrix to be used for retransmission of the second signal vector to the transmitter in accordance with the combining of the first signal vector and the second signal vector and configured to select the precoding matrix based on the calculated effective signal-to-noise ratio,
• wherein the calculation unit is configured to calculate the effective signal-to-noise ratio by calculating post detection signal noise ratio vectors from an effective channel matrix in accordance with the combining of the first signal vector and the second signal vector;
• and calculating the effective signal-to-noise ratio by aggregating the calculated post detection signal-to-noise ratio vectors.