Two‐pilot channel estimation scheme for amplify‐and‐forward relay networks

Abstract

In amplify-and-forward relay networks, the equivalent channel to the destination node is not independent of equivalent noise and the equivalent noise does not follow a Gaussian distribution. Therefore, it is difficult to directly estimate the equivalent channel based on traditional optimal rules. In this paper, we propose a two-pilot estimation (TPE) scheme that decomposes a non-Gaussian noise channel estimation problem into two channel estimation problems in Gaussian noise. In TPE scheme, the relay-destination channel is first estimated by one pilot and the other pilot is used to estimate the equivalent channel with the aid of the estimated relay-destination channel. Simulation results show that the TPE scheme can achieve less estimation error and larger system throughput than other existing channel estimators in slow fading case.Analyze the actual required referential information for optimal detector; Propose a two-pilot-based channel estimation scheme to meet the requirement; Derive the optimal pilot design and power allocation problem. SYSTEM MODELWe consider a wireless network with N randomly placed relay nodes one source node S, and a destination node D like Figure 1. Each node is equipped with only a single antenna and runs with the half-duplex mode. The channels between any two nodes are modeled as quasi-stationary Rayleigh flat fading, which varies from frame to frame. Denote the channel from source to It can be seen that the estimation error of H depends on Var ¹E G º. Thus, we should seek the optimal pilots and optimal power strategy to minimize the upper-bounded estimation error.

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