Throughput analysis of the CSK/SSMA ALOHA with nonorthogonal sequences by non-perfect capture

Abstract

In this paper, the throughput performance of the Code Shift Keying Spread Spectrum Multiple Access (CSK/SSMA) ALOHA system which combines the ALOHA system with CSK using nonorthogonal sequences is analyzed by non-perfect capture. The throughput performance of the CSK/SSMA ALOHA system with nonorthogonal sequences is evaluated when varying the number of concatenations because the nonorthogonal sequences are constructed by concatenating Mcon orthogonal sequences. Moreover, the effect of Channel Load Sensing Protocol (CLSP) is examined. Consequently, the throughput performance varies according to Mcon and the throughput performance improves considerably by using CLSP.

Influence of Channel Estimation Error on Throughput Performance in the Channel Estimation-Oriented Access Control Scheme with Code Shift Keying

“…In the method of the literature [3][4], a burden imposed on the base station becomes heavy because the base station controls network traffic. To overcome these issues, we have investigated a channel estimation-oriented access control scheme using code shift keying (CSK) [5]- [9]. In the system, each user estimates the channel based on the power that the user receives from other users, and then decides whether to transmit the packet or refrain from transmission with a certain probability.…”

Effect of Access Control Scheme based on the Estimation of Offered Load on the CSK/SS Random Access Systems

“…The probability of correct detection of one frame, P c (k 1 , k 2 , · · · , k Mcon ), is given by [10] …”

“…However, the DS/SS ALOHA system has bad throughput performance that is shown in many papers. The Code Shift Keying Spread Spectrum (CSK/SS) ALOHA systems, which belong to the packet radio communications, outperform the DS/SS ALOHA system [8]- [10]. However, in the CSK/SS ALOHA systems, as in the case of the DS/SS ALOHA system, the throughput performance decreases as the network traffic increases.…”

“…In CLSP, the central station controls the number of ongoing packets based on the estimated number of ongoing packets. The throughput performance of the CSK/SS ALOHA systems improves by using CLSP [8] [10]. However, it is difficult to apply CLSP to such networks as ad hoc networks, sensor networks and vehicle to vehicle communications, because CLSP is the access control scheme which is initiative by the central station.…”