6 research outputs found
Joint Adaptive Modulation-Coding and Cooperative ARQ for Wireless Relay Networks
This paper presents a cross-layer approach to jointly design adaptive
modulation and coding (AMC) at the physical layer and cooperative truncated
automatic repeat request (ARQ) protocol at the data link layer. We first derive
an exact closed form expression for the spectral efficiency of the proposed
joint AMC-cooperative ARQ scheme. Aiming at maximizing this system performance
measure, we then optimize an AMC scheme which directly satisfies a prescribed
packet loss rate constraint at the data-link layer. The results indicate that
utilizing cooperative ARQ as a retransmission strategy, noticeably enhances the
spectral efficiency compared with the system that employs AMC alone at the
physical layer. Moreover, the proposed adaptive rate cooperative ARQ scheme
outperforms the fixed rate counterpart when the transmission modes at the
source and relay are chosen based on the channel statistics. This in turn
quantifies the possible gain achieved by joint design of AMC and ARQ in
wireless relay networks.Comment: 5 pages, 4 figures, To appear in the Proceedings of the 2008 IEEE
International Symposium on Wireless Communication Systems (ISWCS), Rykevick,
Island, Oct 200
Joint Adaptive Modulation-Coding and Cooperative ARQ for Wireless Relay Networks
This paper presents a cross-layer approach to jointly design adaptive
modulation and coding (AMC) at the physical layer and cooperative truncated
automatic repeat request (ARQ) protocol at the data link layer. We first derive
an exact closed form expression for the spectral efficiency of the proposed
joint AMC-cooperative ARQ scheme. Aiming at maximizing this system performance
measure, we then optimize an AMC scheme which directly satisfies a prescribed
packet loss rate constraint at the data-link layer. The results indicate that
utilizing cooperative ARQ as a retransmission strategy, noticeably enhances the
spectral efficiency compared with the system that employs AMC alone at the
physical layer. Moreover, the proposed adaptive rate cooperative ARQ scheme
outperforms the fixed rate counterpart when the transmission modes at the
source and relay are chosen based on the channel statistics. This in turn
quantifies the possible gain achieved by joint design of AMC and ARQ in
wireless relay networks.Comment: 5 pages, 4 figures, To appear in the Proceedings of the 2008 IEEE
International Symposium on Wireless Communication Systems (ISWCS), Rykevick,
Island, Oct 200