Successive Interference Cancellation Scheme Research Articles

A matrix-algebraic approach to successive interference cancellation in CDMA

In this paper, we describe linear successive interference cancellation (SIC) based on matrix-algebra. We show that linear SIC schemes (single stage and multistage) correspond to linear matrix filtering that can be performed directly on the received chip-matched filtered signal vector without explicitly performing the interference cancellation. This leads to an analytical expression for calculating the resulting bit-error rate which is of particular use for short code systems. Convergence issues are discussed, and the concept of /spl epsiv/-convergence is introduced to determine the number of stages required for practical convergence for both short and long codes.

Evaluation of a DS/CDMA multiuser receiver employing a hybrid form of interference cancellation in Rayleigh-fading channels

This paper assesses the performance of a multiuser detection DS/CDMA receiver based on a hybrid scheme of successive interference cancellation (SIC) and parallel interference cancellation (PIC). Two configurations of the proposed hybrid IC are presented and compared with existing SIC and PIC schemes. The performance criteria used for comparison are complexity, delay, power control requirements, and average bit-error rate (BER) performance obtained by simulation in Rayleigh-fading channels with additive white Gaussian noise (AWGN). The suggested hybrid IC combines good average BER performance, short delay, acceptable complexity, and also operates under slow power control.

Interference cancellation scheme with simple structure and better performance

The authors propose a new interference cancellation (IC) scheme which has a hybrid structure of the successive IC scheme and the parallel IC scheme. Based on computer simulation results, it is observed that the proposed IC scheme outperforms these two IC schemes for CDMA systems.

A novel CDMA multiuser interference cancellation receiver with reference symbol aided estimation of channel parameters

A novel multistage successive interference cancellation scheme is proposed which operates on the reverse code-division multiple-access (CDMA) link using binary phase shift keying (BPSK) modulation, coherent detection and reference symbols to obtain channel estimates. The results of a single cell multiuser investigation demonstrate increased traffic capacity. However, this increase is initially very moderate due to corruption of the channel estimates by interference from symbols not yet demodulated and cancelled. A modification in the transmitted signal structure addressing this problem is proposed. The results of a single cell analysis of the modified cancellation scheme demonstrate that the system's traffic capacity reaches approximately 80% of that of a multistage successive interference cancelling receiver operating with the perfect knowledge of channel parameters. A subsequent multicell investigation shows that for a hexagonal cell geometry with a path loss exponent of four and without any forward error correction (FEC) coding or cell sectorization, the system capacity compares very favorably with that of the IS-95 system, which employs powerful error control coding. Capacities with other path loss exponents and cell geometries are also investigated. The results show a substantial traffic capacity increase over that of a comparable receiver without interference cancellation.

Analysis of a simple successive interference cancellation scheme in a DS/CDMA system

Compensating for near/far effects is critical for satisfactory performance of DS/CDMA systems. So far, practical systems have used power control to overcome fading and near/far effects. Another approach, which has a fundamental potential in not only eliminating near/far effects but also in substantially raising the capacity, is multiuser detection and interference cancellation. Various optimal and suboptimal schemes have been investigated. Most of these schemes, however, get too complex even for relatively simple systems and rely on good channel estimates. For interference cancellation, estimation of channel parameters (viz. received amplitude and phase) is important. We analyze a simple successive interference cancellation scheme for coherent BPSK modulation, where the parameter estimation is done using the output of a linear correlator. We then extend the analysis for a noncoherent modulation scheme, namely M-ary orthogonal modulation. For the noncoherent case, the needed information on both the amplitude and phase is obtained from the correlator output. The performance of the IC scheme along with multipath diversity combining is studied.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>