In this article, we propose a new scheme for multi user detection (MUD) using the parallel interference cancellation (PIC) technique. This technique provides a good complexity, latency, and performance compromise. Among spread-spectrum techniques, the most popular one is the direct sequence-code division multiple access (DS-CDMA), where each active user’s data is modulated (multiplied) by a uni...

In industry and academia, researchers have given more and more attention to Cognitive Radio (CR). The key idea of CR is to make it possible for a wireless system to find the vacant spectrum and transfer data without interfering with licensed users (LUs). Then, OFDM is proposed as a candidate signaling technology for such applications. However, the sidelobe interference of subcarriers has become...

Multiuser detection/Interference Cancellation techniques have greatly increased the capacity of wireless network. In the present paper, we focus on successive decoding DS{CDMA system. By successively decoding the strongest user and cancelling out its parts from the received signal in the decreasing received power order, the in{ cell interference is minimised. In a multicellu-lar environment, th...

This paper introduces an improved nonlinear parallel interference cancellation scheme for code-division multiple access (CDMA) that significantly reduces the degrading effect on the desired user of interference from the other users that share the channel. The implementation complexity of the scheme is linear in the number of users and operates on the fact that parallel processing simultaneously...

This paper investigates the design of access policies in spectrum sharing networks by exploiting the retransmission protocol of legacy primary users (PUs) to improve the spectral efficiency via opportunistic retransmissions at secondary users (SUs) and chain decoding [2]. The optimal access policy which maximizes the SU throughput under a maximum interference constraint to the PU and its perfor...

Code division multiple access (CDMA) is a powerful multiplexing scheme which is very suited to the optical domain with its broad spectrum. Optical code division multiple access (OCDMA) technique allows multiple users to share the same transmission media by assigning different codes and is a very promising technique for the broadband communication. OCDMA networks can provide all customers with u...

In broadband DS-CDMA uplink transmission using frequency-domain equalization (FDE) without cyclic prefix (CP) insertion, the transmission performance degrades due to inter block interference (IBI) and circular property loss. In this paper, IBI cancellation and circular property loss restoration is proposed and the performance improvement is evaluated by computer simulation. It is shown that ite...

Two kinds of RAKE receiver combining schemes are investigated for a partial parallel interference cancellation (PPIC) technique, including maximal ratio combining (MRC) and minimum mean-squared error (MMSE) combining, in directsequence code-division multiple access (DS-CDMA) ultrawideband (UWB) systems. We use the normalized least meansquared algorithm to approach the MMSE solution for the RAKE...

Multiple-input multiple-output (MIMO) multiplexing is an attractive technique to achieve very high-speed transmission with a limited bandwidth. Recently, we proposed an iterative frequency-domain interference cancellation (FDIC) for single-carrier MIMO (SC-MIMO) multiplexing. In our previous work, assuming that the interference from the other antennas can be perfectly cancelled in FDIC, one-dim...

A well–known receiver strategy for CDMA transmission is iterative soft decision interference cancellation. For calculation of soft estimates, the distribution of residual interference is commonly assumed to be Gaussian. In this paper, we analyze matched–filter based iterative soft decision interference cancellation (MF ISDIC) when utilizing the actual probability density function (pdf) of resid...