A limited and efficient quantized feedback for IEEE 802.11n evolution

In this paper we propose an efficient way to transmit accurate channel estimation to the transmitter when this latter requires them in order to calculate its precoding vectors. Since number of channel coefficients that need to be sent back to the transmitter, especially when the number of transmit and receive antennas as well as the number of subcarriers of OFDM systems increase, studies on limited channel state information (CSI) feedback are worth being carried out. A limited feedback scheme that allows both the accuracy of the feedback to be improved and the feedback amount to be reduced, based on the sending back of the channel impulse response called temporal CSI (TCSI) is proposed. The proposed scheme is straightfully applied to a IEEE802.11n system.