Cooperative Diversity In Wireless Networks Technology:Principles And Performance Analysis

With the development of communication technology, higher communication quality is required. Cooperative diversity is a technique used in wireless networks that realizes spatial diversity without requiring multiple antennas at any node. Single antenna senders become other users'cooperative partner, share the antennas and create virtual antenna arrays. As a result, single antenna devices can also achieve spatial diversity. It has the advantage of increasing channel capacity, reducing transmit power, combating multipath fading and so on. There are a variety of relaying protocols in cooperative diversity including decode-and-forward (DF), amplify-and-forward (AF) as well as coded cooperation(CC). In addition, coded cooperation combines channel coding with cooperative technology thus achieving better performance.There are lots of documents about research on cooperative diversity at home and abroad. In this paper, cooperative diversity is discussed in terms of principle and performance. Then we put emphasis on the principle and introduce decode-and-forward (DF), amplify-and-forward (AF), selection DF(SDF), incremental Relay(IR) as well as coded cooperation(CC). At the same time, we give the study of outage probability and bit error rate (BER) for these schemes.Note that outage probability is studied in most of the papers in the case of high-SNR. We develop a new way to deduce the accurate outage probability in the general case by means of Chi-square distribution and present relative simulation results.Bit error rate (BER) is an important measurement of communication reliability. We present introduction about BER of AF, DF, SDF protocols as well as deduce the BER upper and lower bounds of the AF and DF schemes, analyzing simulations and theoretic results.Cooperative diversity has a good prospect of application and extension and a brief relative introduction is given at the end of the paper. At last, we summarize the follow-up work of the topic.