Performance evaluation for band-limited DS-CDMA communication system

Asano, Yoshihiko; Daido, Y.; Holtzman, J.M.

doi:10.1109/vetec.1993.507512

Cited by 36 publications

(24 citation statements)

References 5 publications

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“…Rather than starting with an expansion in derivatives, one can start with an expansion in differences (Stirling formula) [19,20]. This will yield significant benefits in both accuracy and computational simplicity.…”

Section: The Proposed Approximate Pdf For Loo's Distributionmentioning

confidence: 99%

Approximate Outage Analysis of Land Mobile Satellite Systems in Lognormally Shadowed Rician Channels

Samimi

2010

Wireless Pers Commun

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Among the proposed models for land mobile satellite (LMS) channels, the shadowed Rice model proposed originally by Loo, has found wide applications in different frequency bands. In Loo's model, it is assumed that the received signal is affected by nonselective Rice fading with lognormal shadowing on the direct component only, while the diffuse scattered component has constant average power level. The resulting composite probability density function (PDF) includes an infinite-range integral and is not available in closed-form, thereby making the performance evaluation of LMS communication links in these channels cumbersome. To bypass this problem, in this paper an approximation method is developed which makes it possible to describe the envelope PDF as a sum of weighted Rice's PDFs. Therefore, in contrast with Loo's PDF, the proposed method leads to an easyto-use, closed-form approximate expression for the PDF and also for the most statistical characteristics, such as cumulative distribution function and moments of the signal envelop in shadowed Rice channels. Based on the derived expressions, the performance analysis of a single receiver operating over lognormally shadowed Rice channel is investigated in terms of the outage probability. Numerically evaluated results show the good accuracy of the proposed approximation method.

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Section: The Proposed Approximate Pdf For Loo's Distributionmentioning

confidence: 99%

Approximate Outage Analysis of Land Mobile Satellite Systems in Lognormally Shadowed Rician Channels

Samimi

2010

Wireless Pers Commun

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“…However, we introduced a correction factor of 3/2 because we consider practical square-root raised cosine pulses. Indeed, the performance evaluation with a rectangular pulse shape leads to an overestimation of the system capacity by 3(1−R/4) 2 relative to the evaluation which uses the square-root raised cosine filter with a roll-off factor of R [24]. In order to derive the variance of the residual interference of the groups of users detected by the modes R, D and H, we calculate the variance of the interference generated by each user separately.…”

Section: Resultsmentioning

confidence: 99%

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Al-Turkistany

Helal

Schmalz

2009

Wireless Communications

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SummaryIn this paper, we address the issue of multi-user receiver design in realistic multi-cellular and multi-rate CDMA systems based on performance analysis. We consider the multi-user detection (MUD) technique, denoted interference subspace rejection (ISR), because it offers a wide range of canonic suppression modes that range in performance and complexity between interference cancellers and linear receivers. To further broaden our study, we propose a modified ISR scheme called hybrid ISR to cope better with multi-rate transmissions. The performance analysis, which is based on the Gaussian assumption (GA) and validated by simulations, takes into account data estimation errors, carrier frequency mismatch, imperfect power control, identification errors of time-varying multipath Rayleigh channels and intercell interference. This analysis enables us to optimize the selection of the MUD mode for multi-rate transmissions in different operating conditions. The effectiveness of interference cancellation is indeed investigated under different mobile speeds, numbers of receiving antennas, near-far situations, channel estimation errors, and out-cell to in-cell interference ratios. This investigation suggests that the out-of-cell interference, the residual in-cell interference, the noise enhancement as well as low mobility favor the simplest MUD modes as they offer the best performance/complexity tradeoffs.

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“…. For a 11 > a 21 (<), (1) if a 11 + a 21 < 1.5, then p 1 < p 2 (>); (2) if a 11 + a 21 > 1.5, then p 1 > p 2 (<); (3) if a 11 + a 21 = 1.5, then p 1 = p 2 (refer to Appendix IV for proof).…”

Section: Average Signal-to-interference-plus-noise-ratio Analysismentioning

confidence: 99%

“…The performance analysis of band-limited binary DS-CDMA systems was conducted in Refs. [2,7,12,18]. The optimal band-limited chip waveform in asynchronous DS-CDMA systems with aperiodic random spreading sequences and matched filter receiver was obtained subject to the same system bandwidth and data transmission rate [5].…”

Section: Introductionmentioning

confidence: 99%

Second order polynomial class of chip waveforms for band-limited DS-CDMA systems

Song

Leung

2007

Wireless Pers Commun

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The conventional frequency domain square-root raised cosine (Nyquist) chip waveform has much poorer anti-multiple-access-interference (anti-MAI) capability than the optimal bandlimited waveform in direct sequence code division multiple access (DS-CDMA) systems. However, the digital implementation of the optimal chip pulse is very costly due to the slow decaying rate of the time waveform. In addition, its eye diagram and envelope uniformity are worse than the Nyquist pulse for a wide range of roll-off factor, which will incur performance degradation due to timing jitters and post non-linear processing. In this paper, based on an elementary density function of a second-order polynomial, a class of second-order continuity pulses is proposed. From this class of pulses, we can find some members having faster decaying rate, bigger eye opening, more uniform envelope and stronger anti-MAI capability than the Nyquist waveform. The normalized-bandwidth-pulse-shape-factor product, the decaying rate of the tail of the time waveform, the opening of the eye diagram, and the envelope uniformity of the second-order continuity pulses are addressed in the paper that provide the basic information for the selection of the chip pulse for CDMA systems.

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Performance evaluation for band-limited DS-CDMA communication system

Cited by 36 publications

References 5 publications

Approximate Outage Analysis of Land Mobile Satellite Systems in Lognormally Shadowed Rician Channels

Approximate Outage Analysis of Land Mobile Satellite Systems in Lognormally Shadowed Rician Channels

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Second order polynomial class of chip waveforms for band-limited DS-CDMA systems

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