Weighted cross-layer cooperative beamforming for wireless networks
IEEE Transactions on Signal Processing
Single and multiple relay selection schemes and their achievable diversity orders
IEEE Transactions on Wireless Communications
Network beamforming using relays with perfect channel information
IEEE Transactions on Information Theory
Joint source/relay precoder design in nonregenerative cooperative systems using an MMSE criterion
IEEE Transactions on Wireless Communications
Filter-and-forward distributed beamforming in relay networks with frequency selective fading
IEEE Transactions on Signal Processing
IEEE Transactions on Signal Processing
Beamforming in wireless relay-interference networks with quantized feedback
GLOBECOM'09 Proceedings of the 28th IEEE conference on Global telecommunications
Cooperative transmission for wireless relay networks using limited feedback
IEEE Transactions on Signal Processing
IEEE Transactions on Signal Processing
| Hi-index | 0.15 |
This paper is on quantized beamforming in wireless amplify-and-forward (AF) relay networks. We use the generalized Lloyd algorithm (GLA) to design the quantizer of the feedback information and specifically to optimize the bit error rate (BER) performance of the system. Achievable bounds for different performance measures are derived. First, we analytically show that a simple feedback scheme based on relay selection can achieve full diversity. Unlike the previous diversity analysis on the relay selection scheme, our analysis is not aided by any approximations or modified forwarding schemes. Then, for highrate feedback, we find an upper bound on the average signalto- noise ratio (SNR) loss. Using this result, we demonstrate that both the average SNR loss and the capacity loss decay at least exponentially with the number of feedback bits. In addition, we provide approximate upper and lower bounds on the BER, which can be calculated numerically.We observe that our designs can achieve both full diversity as well as high array gain with only a moderate number of feedback bits. Simulations also show that our approximate BER is a reliable estimation on the actual BER. We also generalize our analytical results to asynchronous networks, where perfect carrier level synchronization is not available among the relays.