Virtual branch analysis of symbol error probability for hybrid selection/maximal-ratio combining in Rayleigh fading

Abstract

Abstract-In this paper, we derive analytical expressions for the symbol error probability (SEP) for a hybrid selection/maximalratio combining (H-S/MRC) diversity system in multipath-fading wireless environments. With H-S/MRC, out of diversity branches are selected and combined using maximal-ratio combining (MRC). We consider coherent detection of -ary phase-shift keying (MPSK) and quadrature amplitude modulation (MQAM) using H-S/MRC for the case of independent Rayleigh fading with equal signal-to-noise ratio averaged over the fading. The proposed problem is made analytically tractable by transforming the ordered physical diversity branches, which are correlated, into independent and identically distributed (i.i.d.) "virtual branches," which results in a simple derivation of the SEP for arbitrary and . We further obtain a canonical structure for the SEP of H-S/MRC as a weighted sum of the elementary SEP's, which are the SEP's using MRC with i.i.d. diversity branches in Rayleigh fading, or equivalently the SEP's of the nondiversity (single-branch) system in Nakagami fading, whose closed-form expressions are well-known. We present numerical examples illustrating that H-S/MRC, even with , can achieve performance close to that of -branch MRC.Index Terms-Diversity combining, error probability, fading channel, maximal ratio combining, selection diversity, virtual branch technique.

Communication in a Poisson Field of Interferers-Part II: Channel Capacity and Interference Spectrum

“…7(a), an increase in b may degrade or improve the performance, depending on the value of the link length r 0 and other parameters. This is because b simultaneously affects both the received signal of interest and the aggregate interferencethe former, through the term 1/r b 0 ; and the latter, through α A and γ A in (14), or through α B , γ B , and V G in (27) and (28).…”

“…B is distributed according to (27); V G is given in (28); and the other parameters have the same meaning as in Section IV-A. When the probe transmitter employs M -PSK and M -QAM modulations with equiprobable symbols, (20) is equivalent to…”

“…Our framework has thus reduced the analysis to a Gaussian problem, where the combined noise W is Gaussian when conditioned on the location of the interferers. The corresponding error probability P e (G 0 , P) can be found by taking the well-known error probability expressions for coherent detection of linear modulations in the presence of AWGN and fast fading [27]- [30], but using 2AV X + N 0 instead of N 0 for the total noise variance. Note that this substitution is valid for any linear modulation, allowing the traditional results to be extended to include the effect of network interference.…”

Signal Processing by Generalized Receiver in DS-CDMA Wireless Communications Systems

“…In traditional HS/MRC scheme, the strongest L signals are selected according to signal-envelope amplitude [29][30][31][32][33][34][35]. However, some receiver implementations recover directly the in-phase and quadrature components of the received branch signals.…”

The Effect of Narrowband Interference on Wideband Wireless Communication Systems

“…Accordingly, we consider independent Nakagami-distributed paths, , with average power and Nakagami parameter . Using the alternative expression for the Gaussian -function [37], one can derive the expectation of (34) over as (37) where (38) is the mean SINR as a function of the average SNR and the average SIR . Note that the approximation developed above is more accurate than the standard Gaussian approximation for the interferer, which would be equivalent to considering only the first term of the expansion in (32).…”