In this paper, a new class of polyphase sequences for CDMA systems and its generation method are suggested, and the correlation properties of the sequence are investigated. The performance of the sequence in quasi-synchronous CDMA (QS-CDMA) systems is investigated under frequency-selective, time-nonselective, slow Nakagami fading channel with additive white Gaussian noise (AWGN). It is shown th...

In this article we propose a solution for the channel decoder in a iterative CDMA receiver. The iterative CDMA receiver resembles a Turbo decoder for serially concatenated convolution codes since the CDMA channel is viewed as a convolutional code. The proposed solution has complexity per bit that is linear in the number of users. For the rst time we observe performance within a fraction of a dB...

CDMA interconnect is a new interconnect mechanism for SoC design. This paper presents how a multiprocessor system can benefit from the use of concurrent data transfers: CDMA interconnect has been adopted to implement the shared bus of a multiprocessor system. Unlike the conventional TDMA bus-based multiprocessor system that shows degradation in performance as the number of processing cores incr...

This study deals with the main characteristics of the Maximal Length, Gold, Kasami, Walsh and variable-length orthogonal codes and their functions in code-division multiple access(CDMA) networks. The important properties of the sequences are examined. A method of multiple spreading for channelization and scrambling in CDMA is described. Auto and cross correlation properties of some codes are me...

The use of a blind scheme for suppressing interference in direct-sequence code-division multiple-access (DS /CDMA) communication systems is investigated. In particular, we use a blind version of the partial-bit DS/CDMA receiver to successfully suppress narrow-band and nearfar multiple-access interference without requiring knowledge of other users’ spreading codes, timing or phase information. P...

Coded modulation scheme introduce robust and reliable system. It combine coding and modulation in one system. This paper show performance of coded modulation with coding rate 2/3, using 8PSK and convolutional coding that implemented in MC CDMA system. MC CDMA is one of multicarrier system that combine OFDM and CDMA so its offer reliable system in frequency selective fading. Decoding process for...

CDMA (QS-CDMA) system, which can allow an increased timing error in synchronized access, is discussed. Average BER performance of the system is analyzed in the condition of different access timing error and different asynchronous users by simulation in AWGN channel. The results show that QS-CDMA system is shown to have great performance gain over the asynchronous system when access timing error...

We consider the other-cell interference evaluation problem in a multi-cell CDMA system by looking at its location-dependence on the location distributions of mobile users in the cells. The goal is to characterize the location-dependent availability of radio resources in CDMA cellular networks. We model the locations of mobile users in a CDMA cell statistically by assuming certain location proba...

In this paper, we propose a new modulation method combining code-division multiple access (CDMA) and quadrature amplitude modulation (QAM), called CDMAQAM. It transmits QAM symbols allocated based on a CDMA signal, and it has the benefit that QAM errors can be recovered if they are in a range where they can be absorbed by CDMA demodulation. We applied the method to railway signaling and develop...