Error probability of interleaved MC-CDMA systems with MRC receiver and correlated Nakagami-m fading channels

The performance of an interleaved multicarrier code-division multiple access system with a maximal-ratio combining receiver is studied with the help of the characteristic function of correlated Nakagami-m random variables. Computer simulations are used to demonstrate the accuracy of the analysis. Based on the analytical results, with an exhaustive search of different subcarrier interleaving schemes, the optimal subcarrier interleaver which provides the minimum bit-error rate (BER) can be achieved. Compared to a random interleaver, the optimal subcarrier interleaver offers significant performance improvement.     

BER performance evaluation for MC-CDMA systems in Nakagami-m fading

Based on the approximation of the sum of several Nakagami-m variables and an alternative expression of the Q-function, an efficient bit error rate (BER) expression is described. The closed BER form is applicable to multicarrier code-division multiple-access (MC-CDMA) systems with equal gain combining (EGC) in frequency selective Nakagami (1960) fading channels.     

BER performance of linear STBC from orthogonal designs over MIMO correlated Nakagami-m fading channels

This paper presents the evaluation of the average bit error rate (BER) performance of linear space-time block codes (STBC) from orthogonal designs over correlated identically distributed Nakagami-m fading channels. Starting from the moment-generating function (MGF) of the multipath component signals at the antenna array elements, analytical expressions of the BER performance for both integral and nonintegral Nakagami-m fading parameters are derived. Closed-form expressions of the spatial cross-correlation function for mobile nonfrequency selective Nakagami-m fading multiple-input-multiple-output (MIMO) channels are obtained, which are valid for small angle-of-arrival (AOA) spread. In this expressions, various parameters of interest, such as the mean AOA of the signal, AOA spread, and array configurations, are all taken into account. The effects of antenna array configuration and the operating environment (mean AOA, AOA spread, Nakagami fading parameter) on the BER performance of the system are illustrated by several numerical examples.     

BER evaluation for general QAM in Nakagami-m fading channels

Evaluation of the bit error rate for general M-ary quadrature amplitude modulation (M-QAM) in Nakagami-m fading channels is presented. The analysis considers real values of the Nakagami fading parameter m, and bit-to-symbol mapping that is not necessarily Gray. Analytical and simulation results are compared to illustrate the accuracy of the analysis, taking as examples non-Gray mapped 16-QAM and 32-cross-QAM constellations.     

Capacity analysis of MIMO MRC systems in correlated rayleigh fading environments

In this paper, we analyze the capacity of multiple-input multiple-output systems employing maximal ratio combining under Rayleigh fading environments in the presence of spatial fading correlation at the transmitter or receiver. Based on statistical properties of the largest eigenvalue of correlated complex Wishart matrices, the exact closed-form expressions for the cumulative distribution function and the probability density function of the output signal-to-noise ratio are presented. The results are used to analyze the outage and ergodic capacities of the systems. The analysis shows that ergodic capacity improves with the increase of the channel correlation coefficient and the analytical results are validated by Monte Carlo simulations.     

BER performance of dual predetection EGC in correlative Nakagami-m fading

In this letter, an approach to the evaluation of the error performance in dual predetection equal-gain combining (EGC) systems over correlated Nakagami-m fading channels is presented. Deriving an infinite series representation for the characteristic function of the sum of two correlated Nakagami-m variables, a closed-form formula is extracted for binary phase-shift keying and coherent binary frequency-shift keying, while several other modulation schemes are studied, capitalizing on a Parsevals's theorem-based approach, previously published. Numerical results and simulations are also presented to illustrate the proposed mathematical analysis and to point out the effect of the input signal-to-noise ratio unbalancing, the fading severity, and the fading correlation on the system's error performance.     

OFDM-MQAM在相关Nakagami-m衰落信道上的性能分析

本文研究频率选择性相关Nakagami衰落信道上采用最大比合并(MRC)分集接收的正交频分多路复用M进制正交幅度调制(OFDM-MQAM)系统.使用矩生成函数(MGF)方法和高斯超几何函数、Appell超几何函数或Lauricella函数,推导任意衰落参数频率选择性相关Nakagami衰落信道上MRC分集接收的OFDM-MQAM系统的误符号率(SER)性能,获得了OFDM-MQAM误符号率的一个新的解析表达式.数值计算结果阐明了多径路径数、Nakagami衰落参数和信道脉冲响应抽头间的相关系数对OFDM-MQAM误符号率性能的影响.     

BER performance of MQAM with L‐branch MRC diversity reception over correlated Nakagami‐m fading channels

Exact and closed form generalized expressions for bit error rate (BER) of M‐ary quadrature amplitude modulation (MQAM) with L‐branch maximal ratio combining (MRC) space diversity reception in fading channels are derived and analyzed. The fading channels are modeled as identical but correlated frequency‐nonselective slow Nakagami‐m fading channels corrupted by additive white Gaussian noise (AWGN). Analytical results obtained are in terms of few finite range integrals with an integrand composed of elementary functions. Because of their simple form, these analytical results readily allow numerical evaluation in cases of practical interest. The results are also general enough to include Nakagami‐m fading channels with and without correlation, no diversity system, Rayleigh fading channels with and without correlation, and AWGN as special cases. The numerical results for the case of 16QAM are shown graphically and also in tabular form in order to examine the effects of fading severity, order of diversity, and branch correlation on the BER performance. The two correlation models considered are constant correlation model and exponential correlation model. One may be interested to know how the BER of MQAM is related to symbol error rate (SER) of MQAM. Therefore, the BER results obtained in this paper are also compared with that obtained directly from the SER. It is expected that the analytical results presented in this paper will provide a convenient tool for design and analysis of a radio communication system with space diversity reception in uncorrelated and correlated fading environment. Copyright © 2002 John Wiley & Sons, Ltd.     

Another look at the performance of MRC schemes in Nakagami-m fading channels with arbitrary parameters

In this letter, we take a close look at the performance of maximal ratio combining (MRC) schemes operating in a flat-Nakagami-m fading environment with arbitrary fading parameters. We derive an expression for the probability density function (pdf) of the output signal-to-noise ratio (SNR) by expressing the moment generating function of the output SNR in the form of multiple Barnes-type contour integrals. By evaluating the inverse transform and converting the multiple contour integrals into infinite series, we are able to derive an expression for the pdf of the output SNR when the Nakagami fading parameters along the diversity branches take on real and arbitrary values. Consequently, the average bit-error rate can now be expressed in terms of Lauricella's multivariate hypergeometric function, which can be easily evaluated numerically. Special cases of the main results reduce to known results in the literature. The results, which apply to independent as well as correlated diversity branches, will be useful for predicting the system performances when the Nakagami fading parameters are real and arbitrary.     

Approximation of SNR statistics for MRC diversity systems inarbitrarily correlated Nakagami fading channels

An approximated probability density function is presented for the SNR in maximal ratio combining diversity systems with an arbitrary number of diversity branches in an arbitrarily correlated Nakagami fading environment. Comparisons between the exact and approximated distribution show good agreement over wide ranges of correlation coefficients     

Average output SINR of equal-gain diversity in correlated Nakagami-m fading with cochannel interference

In mobile radio systems, antenna diversity is used to combat fading and reduce the impact of cochannel interference. In this paper, we analyze the performance of L-branch equal-gain combining receivers over correlated nonidentically distributed Nakagami-m fading channels, in the presence of multiple identical cochannel interferers and additive white Gaussian noise. The performance criterion considered is the average output signal-to-interference-plus-noise ratio, which is obtained in closed form for both independent and correlative fading. Due to the simple form of the derived expressions, they readily allow numerical evaluation for cases of practical interest.     

Outage probability of dual-branch coherent equal-gain combining in correlated Nakagami-m fading

The exact outage probability of mobile radio receivers using dual-branch coherent equal-gain combining is analytically derived for correlated Nakagami-m fading. Expressions in the form of infinite series are obtained for the two cases of identical parameters on both diversity branches, and identical m-parameters (multiples of a half-integer) but not-necessarily identical fading powers on each branch.     

Outage probability of MRC with equi-power cochannel interferers in correlated Rayleigh fading

The outage probability of maximal ratio combining (MRC) in the presence of cochannel interference (CCI) in correlated Rayleigh fading is derived. Under the assumption that the branch gains of the desired user signal and interfering signals have the same correlation matrix, this analysis allows an arbitrary number of cochannel interfering users and an arbitrary number of receiver antennas.     

Outage probability of MRC with unequal-power cochannel interferers in correlated Rayleigh fading

Under the assumption that the branch gains of the desired user signal and interfering signals experience Rayleigh fading and have the same correlation matrix, the outage probability of maximal ratio combining (MRC) in the presence of unequal-power cochannel interference (CCI) is derived for the two cases that the correlation matrix is equi-correlated and that the correlation matrix has different eigenvalues.     

Approximate capacity of OSTBC-OFDM in spatially correlated MIMO Nakagami-m fading channels

Orthogonal space-time block coding in combination with orthogonal frequency-division multiplexing converts frequency-selective multiple-input-multiple-output (MIMO) channels into a set of equivalent scalar Gaussian channels. For MIMO Nakagami-m fading channels in the presence of spatial correlation, a simple and closed-form approximation for the capacity of the equivalent channels is derived with good accuracy.     

Exact BER of rectangular-constellation QAM subjected to asynchronous co-channel interference and Nakagami-m fading

The exact average bit error ratio (BER) of the rectangular quadrature amplitude modulation (QAM) constellation is studied in the context of asynchronous co-channel interference (CCI) and Nakagami-m fading. A new formula is derived for the characteristic function of the CCI, which requires no knowledge of the CCI distribution.     

Capacity analysis of cooperative systems with relay selection in Nakagami-m fading

In this Letter, tight closed-form approximations for the ergodic capacity of dual-hop fixed-gain relaying systems are derived. Our analysis allows for independent Nakagami-m fading channels, with partial relay selection being employed in the first-hop transmission. Simulation results are presented in order to confirm the accuracy of the proposed approximations. It is noteworthy that our formulations can be easily extended for the outage capacity analysis and guidelines for such are provided.     

相关衰落信道上MIMO系统中组合SC/MRC的性能分析

研究相关瑞利衰落信道上MIMO系统中组合发射机选择合并(SC)/接收机最大比合并(MRC)的天线分集系统性能.使用矩生成函数方法,推导相关瑞利衰落信道上采用组合SC/MRC天线分集争相干检测的M进制相移键控(MPSK),M进制正交幅度调制(MQAM),M进制脉冲幅度调制(MPAM)等几种M进制数字调制方式的误符号率精确表达式.数值计算结果阐明相关性和天线阵结构对采用组合SC/MRC天线分集的几种M进制数字调制方式的平均误符号率性能的影响.     

Performance analysis of dual MRC receiver in correlated hoyt fading channels

Performance of a dual maximal ratio combining receiver has been analyzed in correlated Hoyt fading channels. Analytical expressions for the probability density function of the receiver output signal-to-noise ratio (SNR), average SNR, outage probability and average bit error rate performance for binary, coherent and non-coherent modulations have been presented. Numerical results show that for coherent phase shit-keying and differential phase shift-keying modulations, to achieve an ABER of 10^?7, the required excess SNR is relatively small for correlation coefficient (?) less than 0.5 than it is for ? ≫ 0.5.