Performance analysis of ARQ mechanisms considering cooperation and cognition in cellular based relaying systems

Abstract

Wireless relaying technique has been attracted considerable attention as a key technique for improving cell coverage and throughput. Although the wireless relaying technique has many benefits, but there are many problems to solve to use it successfully. One of the biggest problems of the wireless relaying technique is a degradation of system reliability, since the data is transmitted through many wireless links. Therefore, a retransmissions based on an Automatic Repeat reQuest (ARQ) technique will be needed to manage a transmission failure of any link that connects the source node and the destination node. In this thesis, we focus on the performance analysis of various ARQ mechanisms in cellular based relaying systems. First, we analyze the performance of ARQ mechanisms proposed for wireless relaying systems using a discrete-time Markov chain (DTMC) technique. The proposed analytical model considers channel capacity, packet error rate, poisson packet arrival and etc. under a two-hop chain topology. We validate the proposed model by comparing numerical analysis with simulation results. Also, to consider a practical relaying system, we assume a multi-hop system based on the IEEE 802.16j standard and propose an ARQ mechanism achieving the requirements of the IEEE 802.16j standard. In the proposed ARQ mechanism, different ARQ mechanisms are used for uplink and downlink. Also, we propose a rate control algorithm to make up weak points of the proposed ARQ mechanism. By comparing simulation results and numerical analysis, we prove that the proposed ARQ mechanism and the rate control algorithm are very efficient in the multi-hop system based on the IEEE 802.16j standard. Second, we analyze the performance of a cooperative automatic repeat request (C-ARQ) mechanism. The proposed analytical model considers erroneous and non-instantaneous feedback, retransmission timer of the ARQ mechanism, and adaptive modulation and coding (AMC). Using the proposed analytical mo...