Two channel estimation methods for amplify-and-forward relay networks

Exploiting a priori information for iterative channel estimation in block-fading amplify-and-forward cooperative networks

“…For the same strategies, Figure 2 depicts the corresponding FER as a function of E b /N 0 , where E b denotes the received energy per information bit at the destination (see (4)). When exploiting only the pilot symbols for channel estimation, the MAP approach slightly (by about 0.2 dB) outperforms the LMMSE and ML approaches in terms of FER; as compared to the reference system, the FER resulting from MAP estimation is about 2 dB worse.…”

“…The overall noise in the signal received from the relay has a variance depending on the realization of the relay-destination channel, and the overall channel gain is the product of the source-relay and relay-destination channel gains. It has been proposed (e.g., the linear minimum mean-square *Correspondence: nico.aerts@telin.ugent.be TELIN, UGent, Gent 9000, Belgium error (LMMSE) cascaded channel estimation from [4,5]) that the destination estimates the overall channel gain but takes the overall noise variance equal to the variance obtained by averaging over the statistic of the relaydestination channel, whereas in [6] the relay-destination channel gain is estimated separately (and the noise variance computed accordingly) at the expense of a more sophisticated relay (that adds pilot symbols of its own). The LMMSE disintegrated estimation from [5] involves the estimation of the source-relay channel at the relay (which significantly increases relay complexity) and the relay-destination channel at the destination, whereas [7] considers maximum-likelihood (ML) estimation of both these channels at the destination.…”

Performance comparison of cooperative OFDM and SC-FDE relay networks in a frequency-selective fading channel

“…To date, there has been some work on cooperative schemes with pilot-assisted channel estimation (CE) [5]- [8], but the performance of both OFDM and SC-FDE with pilot assisted CE has not been presented. In [5], pilot-assisted CE schemes are investigated using linear minimum mean squared error estimation (LMMSE). In [6], a pilot-assisted CE scheme for the general case of AF relay networks with N relays is presented, where a small number of short pilot symbols are used.…”

Performance Analysis of Cooperative Communication Systems with Imperfect Channel Estimation

“…Thus, it is important to investigate the error performance of AF systems with imperfect CSI. In recent works [11,12], the effects of the channel estimation error on the performance of AF cooperative communication systems have been studied by means of Monte Carlo simulations. While in [13], the error performance of AF system is investigated by using a simple and notional model of the channel estimation error, where the variance of the channel estimation error is assumed to be fixed for all values of the signal-to-noise ratio (SNR).…”