Patent ID: 7917107
Filing Date: 2011-03-29
Classification: H04B,H04L

Abstract:
1. A method for selecting antennas in a multiple-input, multiple-output wireless communications network including a plurality of stations, each station including a set of transmit RF chains and a set of receive RF chains, wherein each RF chain is connectable to a set of antennas, comprising the steps of: transmitting, from a first station to a second station during training, a training frame for each possible subset of the set of antennas, and wherein the set of transmit RF chains are connected to the subset of antennas according to a connection mapping rule while transmitting each training frame; estimating, in the second station, a subchannel matrix for each frame; feeding back, from the second station to the first station, the subchannel matrix for each frame; determining, in the first station, radio frequency (RF) imbalance transmit correction coefficients based on the subchannel matrices fed back by the second station, wherein the first station A has the set of N where represents an equivalent channel involving all RF responses, and h A→B,n i is an actual physical channel coefficient from transmit antenna i to receive antenna n B connected to receive RF chain l B , and β l n (Rx) is a corresponding receive RF response at the second station B, and α li (Tx) is a transmit RF response at the first station A with a connection of transmit antenna i and transmit RF chain l; and multiplying a baseband stream transmitted by selected transmit antennas at the first station by the RF imbalance transmit correction coefficients.