ABSTRACT
This chapter presents the background on cooperative communications and the systems considered. It provides the system model and gives the motivation to use link adaptive transmission techniques for Orthogonal frequency-division multiple access (OFDM(A)) based wireless relay networks. A relay station (RS) using the amplify-forward (AF) scheme amplifies and forwards the signal which is received from the source. With AF based relaying, these two time phases need to have equal duration as the Base Station and the RS transmit with the same constellation. The OFDM modulator consists of Inverse Fast Fourier Transform (FFT), Cyclic Prefix (CP) insertion, parallel to serial converter and digital to analog converter blocks. The OFDM demodulator block consists of analog to digital converter, CP deletion, serial to parallel converter and FFT blocks. The chapter analyses the end-to-end Bit Error Ratio performance of cooperative receive diversity with AF and decode-forward based forwarding schemes.
