Computer Science – Information Theory
Scientific paper
2011-08-23
Computer Science
Information Theory
Submitted to IEEE Trans. Info. Theory
Scientific paper
We study the tradeoff between reliability, data rate, and delay for half-duplex MIMO multihop networks that utilize the automatic-retransmission-request (ARQ) protocol both in the asymptotic high signal-to-noise ratio (SNR) regime and in the finite SNR regime. We propose novel ARQ protocol designs that optimize these tradeoffs. We first derive the diversity-multiplexing-delay tradeoff (DMDT) in the high SNR regime, where the delay is caused only by retransmissions. This asymptotic DMDT shows that the performance of an N node network is limited by the weakest three-node sub-network, and the performance of a three-node sub-network is determined by its weakest link, and, hence, the optimal ARQ protocol needs to equalize the performance on each link by allocating ARQ window sizes optimally. This equalization is captured through a novel Variable Block-Length (VBL) ARQ protocol that we propose, which achieves the optimal DMDT. We then consider the DMDT in the finite SNR regime, where the delay is caused by both the ARQ retransmissions and queueing. We characterize the finite SNR DMDT of the fixed ARQ protocol, when an end-to-end delay constraint is imposed, by deriving the probability of message error using an approach that couples the information outage analysis with the queueing network analysis. The exponent of the probability of deadline violation demonstrates that the system performance is again limited by the weakest three-node sub-network. The queueing delay changes the consideration for optimal ARQ design: more retransmissions reduce decoding error by lowering the information outage probability, but may also increase message drop rate due to delay deadline violations. Hence, the optimal ARQ should balance link performance while avoiding significant delay.
Goldsmith Andrea J.
Gunduz Deniz
Xie Yao
No associations
LandOfFree
The Diversity-Multiplexing-Delay Tradeoff in MIMO Multihop Networks with ARQ does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Diversity-Multiplexing-Delay Tradeoff in MIMO Multihop Networks with ARQ, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Diversity-Multiplexing-Delay Tradeoff in MIMO Multihop Networks with ARQ will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-376937