Redundant Residue Number System Based Multicarrier DS-CDMA for Dynamic Multiple-Access in Cognitive Radios

Abstract

Abstract-Redundant residue number system (RRNS)-based multicarrier DS-CDMA (MC/DS-CDMA) is proposed for dynamic multiple-access (DMA) in cognitive radios (CRs). The proposed RRNS-based MC/DS-CDMA DMA has the merits of low-complexity for implementation, highflexibility for reconfiguration and spectrum handoff, robustness to spectrum varying, and fault-tolerance to errors. Specifically, in our RRNSbased MC/DS-CDMA DMA system, RRNS-based orthogonal modulation aided by MC/DS-CDMA is employed for information transmission. At the receiver, signals are detected subcarrier-by-subcarrier independently based on suboptimum MMSE interference cancellation (SMMSE-IC). In performance study, we model the arrival process of primary users (PUs) in primary radios (PRs) as a Poisson process. Both the bit error rate (BER) performance and throughput performance are investigated. Our studies and performance results show that the RRNS-based MC/DS-CDMA constitutes one of the highly promising DMA schemes for application in CRs. It is capable of achieving a substantial throughput with required quality for the CR systems, while without degrading the quality-of-services (QoS) of the PR systems.

New Error Control Algorithms for Residue Number System Codes

“…Redundant residue number systems (RRNSs) have recently been applied to communication systems, including wireless local area network (WLAN) [1], code division multiple access (CDMA) [2], space-time block codes [3], multicarrier modulation [4], wireless sensor networks [5], and cognitive radio [6]. Redundant residue number systems (RRNSs) have recently been applied to communication systems, including wireless local area network (WLAN) [1], code division multiple access (CDMA) [2], space-time block codes [3], multicarrier modulation [4], wireless sensor networks [5], and cognitive radio [6].…”

Redundant Residue Number System Assisted Multicarrier Direct-Sequence Code-Division Dynamic Multiple Access for Cognitive Radios

“…Motivated by the above concerns, in [7], we have proposed a dynamic multiple-access (DMA) scheme for making use of the time-varying spectrums in CR systems. Our DMA scheme is designed by taking the advantages of both the multicarrier direct-sequence code-division multiple-access (MC/DS-CDMA) [8][9][10][11] and the redundant residue number system (RRNS) [12][13][14][15][16], which is referred to as the RRNS MC/DS-CDDMA for convenience of description in the following texts.…”

“…Owing to the above properties, we can argue that the RRNS MC/DS-CDDMA employing either Type-I.2 or Type-II.1 RMD/MS-MMSE MUD constitutes one of the highly promising DMA schemes for application in CR systems. Note that, in [7], the performance of the RRNS/MC DS-CDDMA systems has been investigated, when a so-called suboptimum MMSE interference cancellation (SMMSE-IC) scheme is employed.…”