Patent ID: 7796630
Filing Date: 2010-09-14
Classification: H04B,H04L

Abstract:
1. A method for estimating channels in a two-hop multi-input-multi-output (MIMO) amplify-and-forward (AF) relay network including a source station (SS), a relay station (RS), and a destination station (DS), wherein there is a first interim channel between the SS and the RS, a second interim channel between the RS and the DS, and an overall channel between the SS and DS, comprising the steps of: transmitting, using the first interim channel, a signal from the SS to the RS; amplifying, in the RS, the signal, while varying a power amplifying matrix during consecutive time intervals; forwarding, using the second interim channel, the amplified signal from the RS to the DS during the consecutive time intervals; estimating, in the DS, the overall channel during each time interval; estimating the first interim channel and the second interim channel based on the estimates of the overall channels obtained during the consecutive time intervals, and wherein each estimate of the overall channel is in a form of a non-linear equation, and further comprising: transforming the non-linear equations to a single linear equation; and solving the single linear equation using a low-complexity linear least square estimation process to obtain the estimates of the first and second interim channels.