Probability of symbol error for MPSK, MDPSK and noncoherent MPSK with MRC and SC space diversity in Nakagami-m fading channel

This paper derives analytically some simple closed form expressions for the average symbol error rate (SER) of M-ary phase shift keying (MPSK), M-ary differential phase shift keying (MDPSK) and noncoherent M-ary frequency shift keying (MFSK) over a Nakagami-m (1960) fading channel with L-fold maximal ratio combining (MRC) and selection combining (SC) space diversity reception. Numerical results demonstrate the error performance improvement by employing MRC and SC diversity reception in the above communications systems and show that MRC improves the error performance more significantly than does simple SC.published_or_final_versio

Performance of generalized selection combining for mobile radio communications with mixed cochannel interferers

The performance of generalized selection combining (GSC) space diversity for mobile radio systems in the presence of multiple cochannel interferers is studied. Two cochannel interference models are considered: 1) L cochannel interferers consisting of L-N Nakagami-m interferers and N Rayleigh interferers and 2) L cochannel interferers in which each interferer follows Nakagami-m distribution for a fraction of time and Rayleigh distribution for the remaining of time. The fading parameters of the Nakagami-m interferers are limited to integer values only. The desired signal is assumed to be Rayleigh faded. Also, all the desired signals and the cochannel interferers received on each branch are independent of each other. Closed-form expressions are derived for the probability density functions (pdfs) of the instantaneous signal-to-interference power ratio (SIR) at the output of the GSC for the two cochannel interference models. Using these SIR pdfs, closed-form expression for evaluating the outage probability and the average bit error probability (BEP) are subsequently derived. A differential phase-shift keying scheme is considered in the derivation. Numerical results showing the influences of various system parameters on the outage probability and the average BEP are then presented.published_or_final_versio

Approximate BER performance of generalized selection combining in Nakagami-m fading

The error performance of generalized selection combining (GSC), which optimally combines the K highest signal-to-noise ratio (SNR) signals out of L total diversity signals, in Nakagami-m fading was recently evaluated using moment generating function (MGF) of the GSC output SNR. However, no single closed-form expression for the MGF exists for arbitrary K and L. In fact, closed-form expression for the MGF is possible only for individual combination of K and L. In this letter, a single closed-form expression for approximating the MGF is, therefore, derived and employed in evaluating the approximate error performance. Although the approximation is only applicable for GSC with K being a factor of L, it nonetheless achieves a high degree of accuracy.published_or_final_versio

Performance analysis of bandwidth efficient coherent modulation schemes with L-fold MRC and SC in Nakagami-m fading channels

This paper presents the average symbol error rates (SERs) of the 16-ary phase shift keying (16PSK), 16-ary amplitude phase shift keying (16APSK) and 16-ary quadrature amplitude modulation (16QAM) with L-fold maximal ratio combining (MRC) and selection combining (SC) space diversity receptions over Nakagami-m fading channels. Numerical results manifested error performance improvement when L-fold MRC and SC diversity receptions were employed. Error performance improvement attributed to an L=2 MRC diversity reception is comparable with that attributed to an L=4 SC diversity reception for the above three 16-ary modulation systems in a Nakagami-m fading channel with m of 5.published_or_final_versio

Combined diversity sequence estimation receiver for wideband digital mobile radio

An investigation is presented into the performance of a novel type of sequence estimation equalisation receiver. The receiver incorporates space diversity to further enhance the signal reception in multipath fading environments. It is shown that the receiver complexity is reduced by approx. 90% with virtually no performance loss compared to that of the MLSE.published_or_final_versio

Regulatory Compliance when the Rule of Law Is Weak: Evidence from China’s Environmental Reform

What drives regulatees’ behaviors when the institution of law is weak? This study seeks to answer the question by examining environmental regulation enforcement in China. Based on survey and interview data on Hong Kong-owned manufacturing enterprises in the Pearl River Delta Region, Guangdong Province, we found that their decisions to adopt basic and proactive environmental management practices were less driven by concerns for legality than by their perceptions of the regulators’ actions and gestures. Enterprises adopted basic environmental practices to avoid potential punishment and more proactive practices to avoid potentially arbitrary impositions from regulatory officials. Regulated enterprises were more likely to adopt both basic and proactive environmental practices if they had less difficulties in understanding the enforced regulations. These findings suggest important ways in which regulatory compliance behaviors in a developmental context may differ from those in Western countries.postprin

Commitment to corporate, social, and environmental responsibilities: an insight into contrasting perspectives in China and the US

This cross-national study investigates antecedents and outcomes of corporate responsibility (CR) practices to stakeholders and the natural environment in the contrasting contexts of China and the US. In general, we found partial support for the proposition that the divergence of CR stakeholder practices across nations is dependent on the institutional environments of business. Whereas customer and community stakeholder practices were found to be more prevalent in US companies, there were no significant country differences in the prevalence of employee, investor, and environmental CR practices. In addition, we found that the relationship between the prevalence of CR practices and business outcomes (financial performance, corporate reputation, and employee commitment) varied depending on the type of CR practice and country

Outcomes of right-lobe and left-lobe living-donor liver transplantations using small-for-size grafts

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The effect of branch correlation in dual MRC, SC and SWC diversity systems for noncoherent MFSK over Nakagami-m fading channels

This paper presents closed form expressions far the average symbol error rate (SER) of noncoherent M-ary frequency shift keying (MFSK) with dual brmtck maximal ratio- combining (MMCl selection combining (SC) and switched combining (SWC) space diversity receptions over correlated Nakagami'm fading channels. Numerical results demonstrate the error performmicg degradation due to ike effects of correlated bmmches in the three diversity combining systems. They also show that there is similar performance degradation in different diversity combining systems when correlation coefficient p is increased from 0 to CkS, Furthermore, the error performance of employing MRC and SC diversity receptions are very close to each other when both the branch correlation and channel fading are severe.published_or_final_versio

Performance anaylsis of BPSK and DPSK systems in the presence of Nakagami-m fading and noisy phase reference

This paper presents closed form expressions to evaluate the average bit error rate (BER) for coherent binary phase shift keying (BPSK) and differential PSK (DPSK) modulations over slow Nakagami-m fading channel with noisy phase reference. The performance degradation due to the noisy phase reference are then investigated with respect to the channel fading parameter m and the phase error θ. The phase error is assumed to be uniformly distributed with maximum phase error . At the average BER of 10(-3), results show that the error performance of the BPSK with 0> 44° is worse than the DPSK with 0=0 for m=9, i.e., the advantage of employing the BPSK over the DPSK is vanished.published_or_final_versio