Multiple access interference (MAI) canceller enhanced RAKE receiver for asynchronous CDMA system in multipath channels

1999 ◽  
Author(s):  
P.J. Chitamu
Keyword(s):  
Multiple Access ◽  
Rake Receiver ◽  
Multiple Access Interference ◽  
Multipath Channels ◽  
Cdma System ◽  
Asynchronous Cdma

scholarly journals Incremental gradient algorithm for multiuser detection in multi-carrier DS-CDMA system under modulation schemes

2018 ◽  
Vol 7 (2.6) ◽  
pp. 311
Author(s):  
Sumitra N. Motade ◽  
Anju V. Kulkarni
Keyword(s):  
Spread Spectrum ◽  
Multiple Access ◽  
Minimum Mean Square Error ◽  
Multiple Access Interference ◽  
Gradient Algorithm ◽  
Channel Noise ◽  
Cdma System ◽  
Communication Performance ◽  
Optimum Performance ◽  
Code Division Multiple

Nowadays, Multicarrier Direct sequence code division multiple access (MC DS-CDMA) systems are used in mobile communication. Performance of these systems are limited by multiple access interference (MAI) created by spread-spectrum users in the channel as well as background channel noise. This paper proposes an incremental gradient descent (IGD) multi-user detection (MUD) for MC DS-CDMA system that can achieve near-optimum performance while the number of users is linear in its implementation complexity.  The IGD algorithm make an effort to perform optimum MUD by updating one user's bit decision each iteration in the best way. This algorithm accelerates the gradient algorithm convergence by averaging. When a minimum mean square error (MMSE) MUD is employed to initialize the proposed algorithm, in all cases tested the gradient search converges to a solution with optimum performance. Further, the iterative tests denote that the proposed IGD algorithm provides significant performance for cases where other suboptimum algorithms perform poorly. Simulation compares the proposed IGD algorithm with the conventional detectors. 

A Review on Successive Interference Cancellation Scheme Based on Optical CDMA Network

2014 ◽  
Vol 35 (4) ◽  
Author(s):  
N. Alsowaidi ◽  
T. Eltaif ◽  
M. R. Mokhtar
Keyword(s):  
Interference Cancellation ◽  
Multiple Access ◽  
Direct Detection ◽  
Multiple Access Interference ◽  
Successive Interference Cancellation ◽  
Optical Cdma ◽  
Spectral Amplitude ◽  
Cdma System ◽  
Spectral Amplitude Coding ◽  
Code Division Multiple

AbstractDue to various desirable features of optical code division multiple access (OCDMA), it is believed this technique once developed and commercially available will be an integral part of optical access networks. Optical CDMA system suffers from a problem called multiple access interference (MAI) which limits the number of active users, it occurs when number of active users share the same carriers. The aim of this paper is to review successive interference cancellation (SIC) scheme based on optical CDMA system. The paper also reviews the system performance in presence of shot noise, thermal noise, and phase–induced intensity noise (PIIN). A comprehensive review on the mathematical model of SIC scheme using direct detection (DS) and spectral amplitude coding (SAC) were presented in this article.

scholarly journals Multiple-Access Interference of Gold Codes in a DS-CDMA System

2015 ◽  
Vol 106 (1) ◽  
pp. 4-10 ◽  
Author(s):  
Olanrewaju B. Wojuola ◽  
Stanley H. Mneney
Keyword(s):  
Multiple Access ◽  
Multiple Access Interference ◽  
Cdma System ◽  
Gold Codes

scholarly journals Multi-code Multicarrier CDMA: Performance Analysis

2017 ◽  
Vol 2 (1) ◽  
pp. 12
Author(s):  
Taeyoon Kim ◽  
Jeffrey G. Andrews ◽  
Jaeweon Kim ◽  
Theodore S. Rappaport
Keyword(s):  
Multiple Access ◽  
Multiple Access Interference ◽  
Cellular Systems ◽  
Cdma System ◽  
Multicarrier Cdma ◽  
Selective Fading ◽  
Next Generation ◽  
Single Carrier ◽  
Data Rates ◽  
Code Division Multiple

A new multi-code multicarrier code division multiple access (MC-MC-CDMA) system is proposed and analyzed in afrequency selective fading channel. By allowing each user to transmit an M-ary code sequence, the proposed MC-MC-CDMA system can support various data rates as required by next generation standards without increasing the interference which is common in general multicarrier CDMA systems. The bit error rate of the system is analytically derived in frequency selective fading, with Gaussian noise and multiple access interference. The results show that the proposed MC-MC-CDMA system clearly outperforms both single-code multicarrier CDMA (MC-CDMA) and single-carrier multi-code CDMA in a fixed bandwidth allocation.This indicates that MC-MC-CDMA can be considered for next generation cellular systems.

Joint Detection Algorithm in Downlink for TD-SCDMA Trunking System

2011 ◽  
Vol 219-220 ◽  
pp. 1165-1169
Author(s):  
Xiao Xiang Shen ◽  
Hui Zhi ◽  
Shi Xiang Shao
Keyword(s):  
Multiple Access ◽  
Multiple Access Interference ◽  
Detection Algorithm ◽  
Cdma System ◽  
Joint Detection ◽  
A Cell ◽  
The Stability

CDMA system is the interference-restricted system, In the TD-SCDMA trunking system, using more than one scrambling in a cell introduces multiple access interference (MAI).This paper analyzes improving the performance of MMSE and PIC Detectors in TD-SCDMA trunking system with different level MAI. It can be seen from the simulation result, the joint detection algorithm can improve the performance of downlink for TD-SCDMA trunking system, and it also can help to keep the stability of this system.

Sign in / Sign up

Export Citation Format

Share Document