Patent ID: 8401057
Filing Date: 2013-03-19
Classification: H04B,H04L

Abstract:
1. An OFDM (Orthogonal Frequency Division Multiplexing)-based relay-assisted channel estimation method, which applies to an AF (Amplify-and-Forward) relaying system and separately estimates a channel from a source node to a relay node and a channel from the relay node to a destination node at the destination node in a wireless communication system in a relay-assisted way, comprising steps of: constructing a system model, wherein a first channel and a second channel are constructed, and wherein the first channel represents the channel from the source node to the relay node and the second channel represents the channel from the relay node to the destination node, and wherein the destination node receives a signal including a kth sub-carrier wave through the first and second channels, and the signal is given by adding a relay-amble signal at the relay node, wherein the relay-amble signal is added to a frame carrying amplified and forwarded signals by the relay node, and transmitted to the destination node through the second channel; estimating a second channel coefficient, wherein after the destination node has received the frame including the relay-amble signal, a second channel estimation is performed to obtain the second channel coefficient through the relay-amble signal; estimating a first channel coefficient, wherein first channel estimation is performed to obtain the first channel coefficient through a ML (Maximum Likelihood) method and the estimate of second channel coefficient; and performing optimum combining, wherein after the first and second channel coefficients have been obtained, a direct path and a relay path are combined to obtain an optimum transmission signal under an RD (Received Diversity) protocol.