Title :
Multiuser CDMA systems employing parity bit selected double spreading
Author :
Shaji, Geethu ; Haris, P.A.
Abstract :
A double spreaded CDMA system employing Parity bit selected spreading sequences is proposed in this paper for improving the Bit error rate (BER) performance of Multiuser CDMA systems. In a CDMA system with parity bit selected spreading sequences (CDMA/PB), the transmitted data bits is used to select the spreading code from a set of mutually orthogonal spreading waveforms allocated to each user. After this the spreaded data is again undergone a second spreading using a unique PN sequence. Multiple Access Interference (MAI) caused in Multiuser CDMA/PB systems can be mitigated by this double spreading method. A new detection algorithm is also used at the receiver for the betterment of the BER performance. The complexity of this proposed method is less compared to Parallel Interference Cancellation (PIC) method in Multiuser CDMA systems. Hadamard codes are used for spreading in the proposed system in order to maintain the orthogonality between the spreading codes.
Keywords :
Hadamard codes; code division multiple access; error statistics; multiuser detection; radiofrequency interference; BER; CDMA/PB systems; Hadamard codes; MAI; PIC method; PN sequence; bit error rate; detection algorithm; multiple access interference; multiuser CDMA systems; orthogonal spreading waveforms; parallel interference cancellation method; parity bit selected double spreading; Bit error rate; Multiaccess communication; Receivers; Spread spectrum communication; Transmitters; Vectors; Wireless communication; BER-Bit error rate; MAI-Multiple access interference; PB-Parity Bit; SS-Spread spectrum;
Conference_Titel :
Computational Systems and Communications (ICCSC), 2014 First International Conference on
Conference_Location :
Trivandrum
Print_ISBN :
978-1-4799-6012-5
DOI :
10.1109/COMPSC.2014.7032616
