Parallel interference cancellation with reduced complexity for multi-carrier spread-spectrum FCDMA

Nahler, A.; Irmer, Ralf; Fettweis, Gerhard

doi:10.1109/isssta.2000.876455

Cited by 6 publications

(4 citation statements)

References 9 publications

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“…The complexity crossing point in Fig. 5 is given by (26) for (27), shown at the bottom of the page. Equation (27) gives a design rule for PIC implementation, specifying which algorithm should be selected for a specific system from a complexity point of view.…”

Section: Computational Complexitymentioning

confidence: 99%

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Reduced and differential parallel interference cancellation for CDMA systems

Nahler¹,

Irmer²,

Fettweis³

2002

IEEE J. Select. Areas Commun.

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Since code division multiple access systems in multipath environments suffer from multiple access interference (MAI), multiuser detection schemes should be used in the receivers. Parallel interference cancellation (PIC) is a promising method to combat MAI due to its relatively low computational complexity and good performance. It is shown in this paper that the complexity of PIC is still high for realistic scenarios in terms of the symbol rate, the number of users, spreading gain, and multipath components. However, two novel methods are introduced to reduce significantly the complexity without sacrificing performance. The first approach, called reduced PIC, takes advantage of the composition of the interference to concentrate interference cancellation only on significant terms. The second approach, called differential PIC, exploits the multistage character of PIC to avoid unnecessary double calculations of certain terms in consecutive stages. It is shown that a combination of both approaches leads to a performance very close to the single-user bound whereas the complexity can be kept on the order of the conventional RAKE receiver.

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Section: Computational Complexitymentioning

confidence: 99%

“…In this section, one modification of the PIC is presented to reduce the computational complexity significantly. This method is the so-called R-PIC, which was first described by the authors in [26]. It works only for the NB-PIC as will be clear later.…”

Section: Reduced Pic (R-pic)mentioning

confidence: 99%

Reduced and differential parallel interference cancellation for CDMA systems

Nahler¹,

Irmer²,

Fettweis³

2002

IEEE J. Select. Areas Commun.

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“…PIC schemes for multicarrier DS-CDMA schemes have n studied in [27][28][29]. These studies consider hard ision (HD) PIC receivers, where hard bit decisions are ie on the output of the MFs, which are then is used to fnerate and cancel the MAl in parallel.…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis of Parallel Interference Cancellation in Multicarrier DS-CDMA Systems

Kumar¹,

Chockalingam²

2005

IETE Journal of Research

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In this paper, we present and analyze the performance of a parallel interference cancellation (PIC) scheme for multicarrier (MC) direct-sequence code-division multiple-access (OS-COMA) systems. At each cancellation stage in the proposed PIC scheme, on each subcarrier, a weighted sum of the soft outputs of the other users in the current stage is cancelled from the soft output of the desired user (rather than making hard bit decisions of the other users and regenerating and canceling the interfering signals) to form the input to the next stage. At the last stage, the interference cancelled outputs from all the subcarriers are maximal ratio combined (MRC) to form the decision statistic. The scheme has the advantage of not requiring the amplitude estimates of the other users. We derive analytical expressions for the bit error rate (BER) at different stages in the proposed PIC scheme on Rayleigh fading channels. Analytical results are found to agree well with the simulation results. The results show that the proposed PIC scheme offers better interference suppression capability than the conventional matched filter (MF) receiver. We also obtain bounds on the coded BER of the proposed PIC scheme for a convolutionally coded multicarrier OS-COMA system where the PIC-MRC output feeds a soft decision Viterbi decoder.

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“…In this paper, we consider parallel interference cancellation (PIC) for multicarrier DS-CDMA. PIC schemes for multicarrier DS-CDMA have been studied in [4]- [5]. These studies consider hard decision PIC receivers, where hard bit decisions are made on the output of the matched filters (MF), which are then is used to regenerate and cancel the multiple access interference (MAI) in parallel.…”

Section: Introductionmentioning

confidence: 99%

Parallel interference cancellation in multicarrier DS-CDMA systems

Kumar

Chockalingam

2004

2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577)

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Abstract-In this paper, we present and analyze the performance of a parallel interference cancellation (PIC) scheme for multicarrier (MC) direct-sequence code-division multiple-access (DS-CDMA) systems. At each cancellation stage in the proposed PIC scheme, on each subcarrier, a weighted sum of the soft outputs of the other users in the current stage is cancelled from the soft output of the desired user (rather than making hard bit decisions of the other users and regenerating and canceling the interfering signals) to form the input to the next stage. At the last stage, the interference cancelled outputs from all the subcarriers are maximal ratio combined (MRC) to form the decision statistic. The scheme has the advantage of not requiring the amplitude estimates of the other users. We derive analytical expressions for the bit error rate (BER) at different stages in the proposed PIC scheme on Rayleigh fading channels. Analytical results are found to agree well with the simulation results. The results show that the proposed PIC scheme offers better interference suppression capability than the conventional matched filter receiver. We also obtain bounds on the coded BER of the proposed PIC scheme for a convolutionally coded multicarrier DS-CDMA system where the PIC-MRC output feeds a soft decision Viterbi decoder.

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Parallel interference cancellation with reduced complexity for multi-carrier spread-spectrum FCDMA

Cited by 6 publications

References 9 publications

Reduced and differential parallel interference cancellation for CDMA systems

Reduced and differential parallel interference cancellation for CDMA systems

Performance Analysis of Parallel Interference Cancellation in Multicarrier DS-CDMA Systems

Parallel interference cancellation in multicarrier DS-CDMA systems

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