M-ary quadrature amplitude modulation (M-ary QAM) is an attractive technique to achieve high rate transmission without increasing the bandwidth in wireless communication systems. A great deal of attention has been devoted to the study of bit error rate (BER) performance of M-ary square QAM constellations. Approximate expressions for bit error probabilities of M-ary square QAM have recently been developed in ,  based on signal-space concepts and recursive algorithms, respectively. However, it is only recently that an exact generalized closed-form expression for the BER of M-ary square QAM constellation has been developed . In this paper, we extend our previous work  to an arbitrary I × J rectangular QAM (R-QAM) scheme. A general closed-form expression for the exact BER performance of an arbitrary I × J R-QAM with Gray code mapping is derived and analyzed under an additive white Gaussian noise (AWGN) channel. The BER performance is also analyzed under fading channels. It is shown that there is a noticeable deviation in the BER performance between the approximation and exact expression over low SNR values.
|Number of pages||4|
|Journal||Conference Record of the Asilomar Conference on Signals, Systems and Computers|
|State||Published - 2001 Jan 1|