Performance Analysis of Non-Coherent Multiple-Access Technique Using Different Modulations

Document Type : Original Article

Authors

1 Modern Academy for Engineering& Technology, Cairo, Egypt.

2 Egyptian Armed Forces, Egypt.

Abstract

Direct sequence (DS) and frequency hopping (FH) are two conventional types of spread spectrum multiple access techniques (SSMA). Recently a hybrid combination between them (hybrid SFH/DS SSMA) are attractive because they can combine the advantages while avoiding some of their disadvantages. The paper presents the throughput and delay analysis when it is required to transmit data over a packet switched code division multiple access network based on the hybrid SFH/DS SSMA. The performance is discussed assuming noncoherent reception of synchronous type hybrid system operating through additive white Gaussian noise channels, and employing different modulation techniques, those are binary frequency shift keying BFSK , M-ary FSK with noncoherent demodulation, as well as the system with differential phase shift keying modulation DPSK. Two closed form for the different modulation types are derived. One of them is probability of error (BER) as a function of the signal to noise ratio (SNR), the other one is the system throughput. Moreover, the paper presents a performance comparison between the hybrid SFH/DS SSMA , pure SFH, and pure DS systems taking the throughput and the delay as performance measures.

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