The effect of spreading gain control on a CDMA slotted ALOHA system

2011

This research aims to investigate the throughputs of DS-CDMA with S-ALOHA systems over Nakagami/Nakagami dual-path gain fading models with capture effects. The effects of fading on bit error rates (BERs) have been analysed by taking path gains into consideration. Due to the discrepancy between path gain for the desired signals and path gain for interferences, the BERs employed in our computations are the BERs of two different path gain models. Research indicates that the throughputs of DS-CDMA with S-ALOHA steadily increase as the parameters of fading signals m and the length of code N progressively enhance. Likewise, the throughputs of DS-CDMA with S-ALOHA gradually step-up as the value of capture ratio Q and the number of users K progressively step-down.

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“…with p A (a) is the pdf of A given by (21). Furthermore, BERs of CDMA with two path gain models fading channel Nakagami/Nakagami can be calculated by substituting (21) and (22) to (23):…”

Section: Bit Error Rates (Bers)mentioning

confidence: 99%

Section: Capture Probabilitymentioning

confidence: 99%

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Capture Delay Analysis on the Throughputs of Direct-Sequence Code Division Multiple Access (DS-CDMA) with Slotted-ALOHA (S-ALOHA) Systems over Nakagami/Nakagami Fading Channels

2011

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“…Research on S-ALOHA adaptive CDMA based on BPSK modulation technique over AWGN channel with capture effects results in the bigger throughputs of the systems [8][9][10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

“…In fact, this algorithm has lead to the reasonable increase of the throughputs of adaptive S-ALOHA CDMA [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Throughput Analysis of Adaptive Slotted-ALOHA CDMA over a Multipath Fading Channel with Capture Effects

2009

This paper aims to investigate the performance of adaptive slotted-ALOHA direct sequence code division multiple access (DS-CDMA) over a multipath fading channel with capture effects. The transmission rate control algorithm has been proposed in response to current traffic conditions. Furthermore, since the performance of S-ALOHA DS CDMA shall decrease in the presence of fading channel environments the capture effect technique has been subsequently proposed. Accordingly, the effectiveness of the throughputs relies on the value of capture probability and the probability of packets being successfully sent. Research indicates that the throughputs of S-ALOHA DS-CDMA (using the following transmission rates: v b/s, 2v b/s, 4v b/s) with capture effects and adaptive S-ALOHA DS-CDMA with capture effects shall increase inverse proportionally to the length of bits (B), the value of different number of paths L p , as well as capture ratios Q.

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Differential Maximum Ratio Combining (MRC)-Based Throughput Analysis on Dual-Fading Models of Slotted-Aloha CDMA Systems

2014