Generalized Rake Receiver for Spreading-IFDMA Systems
نویسندگان
چکیده
Spreading-Interleaved Frequency Division Multiple Access (IFDMA) providing code domain multiplexing for one IFDMA channel shows improved spectrum efficiency and good compatibility with CDMA systems while maintaining advantages of IFDMA systems. A generalized Rake receiver for Spreading-IFDMA is proposed in this paper, which combines jointly derepetition, equalization, and de-spreading processing. Similar to the conventional CDMA systems, the guard interval in Spreading-IFDMA symbols is not necessary, which means that spectrum efficiency can be further improved over IFDMA systems. With digital simulations and performance analysis, the proposed generalized Rake receiver demonstrates better BER performance, robustness, and lower computational complexity.
منابع مشابه
Analysis of the RAKE receiver performance in low spreading gain DS/SS systems
In wideband DS-SS systems the Rake receiver is commonly used to utilize the multipath diversity of the mobile radio channel. In the case of good spreading code correlation properties the multipath components of the received signal can be separated with low interpath interference (IPI). At low spreading gains the good correlation properties of the spreading codes are lost and the Rake receiver p...
متن کاملChaos-Based Asynchronous DS-CDMA Systems and Enhanced Rake Receivers: Measuring the Improvements
Results of recent theoretical investigations highlighted that the use of chaos in direct-sequence code-division multiple access (DS-CDMA) systems may lead to nonnegligible improvements in communication quality for several scenarios. We here briefly review the main steps in this derivation and report the experimental verifications of the corresponding theoretical prediction. With this, we confir...
متن کاملPre-rake Diversity with Generalized Orthogonal Codes and Imperfect Channel Conditions for Fdd/ds-cdma Systems
The Pre-Rake diversity combining technique decreases the complexity, size and cost of the mobile unit while achieving the same inter symbol interference (ISI) mitigation effects of conventional Rake receiver for direct sequence code division multiple access (DS-CDMA) systems. The technique is based on preprocessing of signal at the transmitter relying on knowledge of the channel state informati...
متن کاملDifferential Space-Time Block Code Modulation for DS-CDMA Systems
A differential space-time block code (DSTBC) modulation scheme is used to improve the performance of DS-CDMA systems in fast time-dispersive fading channels. The resulting scheme is referred to as the differential space-time block code modulation for DS-CDMA (DSTBC-CDMA) systems. The new modulation and demodulation schemes are especially studied for the down-link transmission of DS-CDMA systems...
متن کاملOn interpath interference suppression by MLSE detection in DS/SS systems
In wideband DS/SS systems the Rake receiver is commonly used to attain a diversity gain by taking advantage of the good correlation properties of the spreading codes in order to separate the multipath components of the received signal. However, at low spreading gains the good correlation properties of the spreading codes are lost and the Rake receiver performance is severely degraded by interpa...
متن کامل