Patent ID: 8259835
Filing Date: 2012-09-04
Classification: H04B,H04L

Abstract:
1. A wireless transmission system comprising: a base station configured to transmit wireless signals; a memory associated with the base station, the memory configured to store a variable size codebook comprising i) a first codebook having a codebook size comprising a first plurality of precoding matrices for precoding the wireless signals, and ii) a second codebook having a codebook size comprising a second plurality of precoding matrices for precoding the wireless signal; a terminal configured to receive wireless signals; channel state measuring circuitry associated with the terminal, the channel state measuring circuitry configured to measure transmission conditions of a wireless communication channel between the base station and the terminal; a codebook selector associated with the terminal, the codebook selector configured to select a size of a codebook based on i) an expected throughput for each of a plurality of different codebook sizes given the channel state information measured by the channel state measuring circuitry and ii) channel overhead associated with each of the plurality of different codebook sizes; a feedback transmitter associated with the terminal the feedback transmitter configured to wirelessly transmit an indicator of a codebook corresponding to the selected size of the codebook from the terminal to the base station; and a feedback receiver associated with the base station, the feedback receiver configured to receive the indicator of the codebook from the terminal, wherein the base station is configured to select a codebook size based on the indicator of the codebook from the terminal, and wherein the base station is configured to select a precoding matrix from a codebook selected by the base station for precoding wireless signals to be transmitted from the base station.