Cross layer design of protocols for cooperative networks

Abstract

To mitigate the transmission impairments inherent in a wireless channel, several di- newlineversity schemes have been proposed. Multiple input multiple output (MIMO) system newline newlineachieves diversity by transmitting/receiving signals through multiple antennas equip- newlineped at the transmitter and receiver. Cooperative communication at the physical layer newline newlineis a cost effective alternative to MIMO systems. It achieves diversity by transmit- newlineting/receiving signals through the antennas located at the neighboring nodes. This newline newlinediversity known as cooperative diversity can achieve the same diversity gains offe- newlinered by MIMO systems. newline newlineCooperative communication at the physical layer offers several benefits which newlineinclude reduced interference, improved network capacity, extended coverage area, newlineimproved bit error rate (BER) performance, and extended network lifetime. The newline newlineconcept of cooperation/relaying can be extended to the higher layers of the proto- newlinecol stack to achieve the gains offered by cooperative communications, but without newline newlineincurring expensive signal processing and complicated physical layer features. The newlineconcept of cooperative communications integrated into the medium access control newline newline(MAC) layer has led to the development of cooperative MAC protocols. These pro- newlinetocols provide the benefits of cooperative diversity in a wireless local area network newline newline(WLAN) environment; however, in a multi-hop network with multiple flows, they newlinemay increase the interference levels and significantly reduce the performance gains. newlineThe routing protocols that utilize the idea of cooperation are known as cooperative newlinerouting protocols. The cooperative routing protocols can improve the performance of newlinemulti-hop wireless networks. newline