Minimum Selection Generalized Selection Combining Research Articles

Secrecy analysis of cognitive radio network with MS-GSC/MRC scheme

We propose and analyze minimum selection-generalized selection combining (MS-GSC) at secondary receiver (SR) with maximal ratio combining at eavesdropper (ER) to enhance data security at physical layer. We consider an underlay cognitive radio network (CRN) where SR and ER are equipped with multiple antennas, and secondary transmitter (ST) has single antenna with a primary user. Passive eavesdropping is also taken into account.This work is aimed to find the effect of MS-GSC diversity technique on secrecy outage probability (SOP). We derive a closed-form expressions for the exact and asymptotic SOP. Our results show a positive impact on SOP with an increase in diversity branches and also reveal the effect of a primary user on secondary network.

Performance Analysis of Orthogonal Space-Time Block Code With Minimum-Selection Generalized Selection Combining Receiver Over Rayleigh Fading

An orthogonal space-time block code (OSTBC) with a minimum-selection generalized selection combining (MS-GSC) receiver is proposed and analyzed. The motivation behind the proposition of this scheme is a reduction in complexity and processing power at the receiver, compared with a conventional OSTBC system utilizing the maximum-ratio-combining receiver. In addition, it was shown that the OSTBC/MS-GSC can achieve similar performance, compared with the OSTBC/GSC with reduced processing when the predetermined threshold is optimized. In the analysis of this OSTBC/MS-GSC system over a Rayleigh-fading channel, the moment-generating function is presented, where it can be conveniently used to numerically compute the symbol error rate (SER). The average number of branches that is being selected for processing at the receiver is computed and compared. The analytical results are validated by the simulation results.

Performance of Adaptive MS-GSC in the Presence of Cochannel Interference

Minimum-selection generalized selection combining (MS-GSC) has been proposed as a power-saving variant of conventional generalized selection combining (GSC). Existing performance results of this scheme are limited to interference-free environments under multipath fading. This paper addresses the scenario when the received desired signal on each diversity branch is corrupted by multiple interfering signals and background noise, wherein desired and undesired signals undergo mutually independent Rayleigh fading. In the absence of perfect tracking of the instantaneous interference power on diversity branches, the adaptation thresholds that are set on the combined signal-to-noise ratio (SNR) to enhance either the spectral efficiency or power efficiency in noise-limited environments may not guarantee the target performance. This paper aims to study the effect of cochannel interference on the performance of bandwidth- and power-efficient SNR-based MS-GSC. Through the analysis, new analytical results for some important performance measures of adaptive MS-GSC schemes are presented. Numerical comparisons to clarify the impact of cochannel interference on the achieved performance of the adaptation schemes under consideration are provided.

Finger management schemes for RAKE receivers with a minimum call drop criterion

We propose and analyze in this letter new finger management techniques which are applicable for RAKE receivers operating in the soft handover region. These schemes employ "distributed" types of generalized selection combining (GSC) and minimum selection GSC schemes in order to minimize the impact of sudden connection loss of one of the active base stations. By accurately quantifying the average error rate, we show through numerical examples that our newly proposed distributed schemes offer a clear advantage in comparison with their conventional counterparts.

Adaptive generalized selection combining (A-GSC) receivers

We introduce an adaptive generalized selection combining (A-GSC) receiver that can be efficiently applied in diversity rich fading environments such as in ultra-wideband applications. The branches that participate in the combining process are selected taking into account the quality of both the total combining output signal-to-noise ratio (SNR) and the individual SNR of each branch. The proposed scheme achieves better adaptation to channel conditions compared to other competing schemes such as normalized threshold GSC (NT-GSC), minimum selection GSC (MS-GSC) or minimum estimation and combining GSC (MEC-GSC), with no further complexity. The A-GSC receiver compromises between the power consumption, hardware complexity and performance gain that each additional diversity branch induces, resulting in significant savings in power and computational resources.

Adaptive rake combining in the soft handover region

We propose and analyze new finger assignment schemes which are applicable for RAKE reception in the soft handover region. These schemes rely on variants of the conventional generalized selection combining (GSC) and the minimum selection GSC schemes in order to choose an acceptable base station and its corresponding paths. Relying on some recently derived results on order statistics, we investigate the average error rate performance as well as the average number of estimated and combined paths of the proposed schemes over independent and identically distributed Rayleigh fading channels. The mathematical formalism is illustrated with few selected numerical results that show the tradeoff between performance and processing power consumption.

Transactions papers - Minimum selection GSC with down-link power control

We propose and analyze in this paper two new adaptive power controlled minimum selection generalized selection combining (MS-GSC) diversity schemes. The key idea behind these two schemes is to request the transmitter to vary its power level during very adverse channel conditions in order to communicate with the minimum required quality of service. For each scheme, four power control variants accounting for practical implementation constraints including discrete power levels and transmitter gain saturation are proposed and studied. Selected numerical examples, show that ideal continuous power control lowers the average bit error rate of MS-GSC and makes it always meet the specified target quality of service at the expense of an increase in the transmitter gain. Additional numerical examples, show that the power control variants that take into account practical implementation constraints conserve the main features of the ideal continuous power algorithm.

Exact Error Rate Analysis of Output-Threshold Generalized Selection Combining (OT-GSC)

Generalized selection combining (GSC) is one of the most widely investigated low-complexity diversity techniques. Recently, output-threshold GSC (OT-GSC) was proposed as a power-saving variant of traditional GSC scheme. In this paper, we present an exact performance analysis of OT-GSC over Rayleigh fading channels. In particular, we derive the cumulative distribution function (CDF), probability density function (PDF) and moment generation function (MGF) of the combined SNR with OT-GSC. Then, we apply these results to study the outage probability and average error rate performance of OT-GSC. This analysis allows for a thorough and accurate comparison of OT-GSC with other variants of GSC, such as minimum selection GSC.

New results on ordered statistics and analysis of minimum-selection generalized selection combining (GSC)

Diversity combining techniques improve the performance of wireless communication systems at the cost of increased power consumption. Minimum-selection generalized selection combining (MS-GSC) scheme has been proposed as a power saving implementation of conventional generalized selection combining (GSC) scheme. In this paper, noting that previous analytical results on the error rate of MS-GSC are approximate, we carry out a thorough and exact analysis for MS-GSC. In particular, based on a new result on order statistics, we obtain the statistics of the combined SNR with MS-GSC and we then apply these results to analyze the performance of MS-GSC over fading channels. We derive the closed-form expressions of important performance measures, including outage probability and average error rate, for the Rayleigh fading scenario. In addition, we investigate the average number of active MRC branches with MS-GSC, as a quantification of the power saving

Minimum Selection GSC in Independent Rayleigh Fading

We analyze the error performance of minimum selection generalized selection combining (MS-GSC), in which the minimum number of diversity branches are selected such that their combined signal-to-noise ratio (SNR) is above a given threshold. A flat Rayleigh fading channel with independent and distinctly distributed branch SNRs is considered. By transforming the ordered instantaneous branch SNRs to their differences, we derive the distribution of the number of selected branches in closed form. We then modify the derivation of this distribution to get the characteristic function (cf.) of the combiner output SNR. This cf. is used to obtain the symbol error probability for different coherent digital modulation schemes.