Peak-to-average power ratio analysis in multicode CDMA

Sathananthan, K.; Tellambura, Chintha

doi:10.1109/vetecf.2002.1040394

Cited by 13 publications

(13 citation statements)

References 20 publications

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“…(4) This distribution has been estimated in [9] as The block diagram of proposed PAPR reduction method is shown in Fig.2. The difference of proposed system with conventional MC-CDMA system in Fig.1 is the computation vector C from incoming information data.…”

Section: B Ccdf Of Paprmentioning

confidence: 99%

“…Along with PAPR reduction, error-correcting capability of codes for MC-CDMA was also derived. In [9], the authors have analyzed statistical characteristics of MC-CDMA and proposed two types of multiple signal representation technique, which are SLM and PTS to reduce PAPR in MC-CDMA. PTS and SLM can reduce PAPR efficiently, but the additional side information about the phase rotation is corrupted by noise or interference in channel.…”

Section: Introductionmentioning

confidence: 99%

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A PAPR Reduction Method using Constraint Code in Multicode CDMA System

Ryu

Kim

Lee

et al. 2007

2007 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing

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Multicode -Code Division Multiple Access (MC- CDMA) system is very good for the several kinds of service rates with various quality of service requirement because it can affordable by assigning multiple codes and controlling the flexible capacity. However, the so many multi-code signals are summed in the time domain so that it suffers from the serious problem of high peak to average power ratio (PAPR). Therefore, the expensive linear amplifier or large input back-off is necessary to overcome the problem but it makes power consumption of high power amplifier (HPA) very poor. In this paper, we propose a new method that can reduce PAPR efficiently by constraint codes based on the opposite correlation property of the incoming information data. PAPR reduction performance depends on the length and indices of constraint codes in the MC-CDMA system. There is a trade-off between PAPR reduction and the length of constraint codes. We also study the BER improvement in AWGN channel. The simulation results show that BER performance can be very close to the linear amplifier in two cases: 1) when the exact constraint codes are used without input back-off and 2) when a few constraint codes are used with small input back-off.

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Section: B Ccdf Of Paprmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A PAPR Reduction Method using Constraint Code in Multicode CDMA System

Ryu

Kim

Lee

et al. 2007

2007 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing

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“…The phase factor is usually chosen as Bv = {± 1 or Bv = _±1, ±j }. The time domain signal after weighted sum combination of sub-blocks is represented as x = IFFT(Ev Bv X xv) = Ev 1 Bv * IFFT(Xv) (6) Therefore, the PAPR performance and the computational complexity of PTS depend on the sub-block partition method. The sub-block partition techniques of PTS can be classified into three categories; adjacent sub-block partition, interleaved sub-block partition, and random sub-block partition.…”

Section: Introductionmentioning

confidence: 99%

An enhanced adjacent partitioning PTS technique with low computational complexity

Lee¹,

Park

Kim

2007

2007 16th IST Mobile and Wireless Communications Summit

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One of the major drawbacks of OFDM system is the high peak-to-average power ratio (PAPR). This high PAPR causes nonlinear distortion of the high power amplifier (HPA). Among the studies for PAPR reduction, the partial transmit sequence (PTS) is an attractive technique to prevent nonlinear distortion. However, it causes high computational complexity. Moreover, although the random sub-block partition method can obtain the optimum PAPR reduction, it is difficult to design the random sub-block partition method in a systematic manner. In this paper, we propose a new systematic sub-block partition method which shows low computational complexity and effective PAPR reduction. Simulation results show that the PAPR performance of the proposed PTS is closely similar to the random partitioning PTS, while it has low computational complexity.Index Terms-orthogonal frequency division multiplexing, peak-to-average power ratio, partial transmit sequence.sub-block partition method which obtains low computational complexity and effective PAPR reduction. This paper is organized as follows: Section II presents the OFDM system and ordinary PTS. Section III introduces the proposed PTS and discusses the computational complexity. The simulation results of the proposed PTS as compared with ordinary PTS are shown in Section IV. Finally, the conclusions are presented in Section V. II. SYSTEM MODELA. OFDM and PAPR An OFDM signal is the sum of many overlapping orthogonal sub-channels of equal bandwidth. The OFDM signal of N subcarriers is given by

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“…This summation of n signals results in high peaks (present at the forward link of transmitter), which can be as large as n times the average signal power. Typically, n = 2 m where m lies between 2 and 6 [1][2][3]. Therefore, to transmit MC-CDMA signals without distortion we need an expensive power amplifier (PA) that operates in its linear region [1,2,4].…”

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confidence: 99%

Algorithm for reducing PAPR of Multicode CDMA using Reed–Muller codes

Hasan

Siddiqui

2016

Electron. lett.

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A new algorithm for reducing peak-to-average power ratio (PAPR) of multicode code division multiple access (MC-CDMA) systems under binary PSK modulation is presented. The algorithm is based on Reed-Muller (RM) codes that are modified by finding a suitable binary sequence that minimises the PAPR of the MC-CDMA. Three types of RM codes are investigated: namely, zero order, first order and second order. Simulation studies conducted show that the proposed algorithm achieves transmitter power savings of up to 6 dB. Zero-order and first-order codes exhibit 0 dB PAPR, while several others maintain a constant and low PAPR as compared with the original MC-CDMA systems.Introduction: Multicode code division multiple access (MC-CDMA) is based on summation of n channels or signals of basic data rates from an orthogonal set called Walsh-Hadamard transform (WHT) sequences. This summation of n signals results in high peaks (present at the forward link of transmitter), which can be as large as n times the average signal power. Typically, n = 2 m where m lies between 2 and 6 [1-3]. Therefore, to transmit MC-CDMA signals without distortion we need an expensive power amplifier (PA) that operates in its linear region [1,2,4]. Since these peaks occur only occasionally, using a PA that does not distort the high peak signals would be expensive, unrealistic and highly inefficient.The high peaks of the signal are usually measured by a well-known parameter called peak-to-average power ratio (PAPR) [5]. The objective then is to reduce PAPR that reduces the high signal peaks.Paterson [1] has developed constant-amplitude codes for MC-CDMA from bent function, Kerdock and Delsarte-Goethals codes. While Schmidt [6] has designed quaternary constant-amplitude codes for MC-CDMA. Both of them have reduced the PAPR in MC-CDMA to the value of 1. Their construction of codes is based on complex mathematics. Several other methods have been proposed to reduce the PAPR. Some of these are reported in, for example, [3,7] where they have used partial transmit sequence (PTS) and selected mapping (SLM) to reduce PAPR, at the expense of complexity [2,8]. A consolidated comparison table showing other algorithms can be found in [9].In this Letter, we propose a new and simple approach to reduce PAPR of MC-CDMA using Reed-Muller (RM) codes. These RM codes are one of the oldest and well understood families of codes. The great merit of RM codes is that they are relatively easy to decode using majority logic circuits [10].Binary RM code may be defined as RM(r, m) of order r, r = 0, 1, …, m [9, Chapter 3, p.57] has the triplets (n, k, d ) as follows:

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Peak-to-average power ratio analysis in multicode CDMA

Cited by 13 publications

References 20 publications

A PAPR Reduction Method using Constraint Code in Multicode CDMA System

A PAPR Reduction Method using Constraint Code in Multicode CDMA System

An enhanced adjacent partitioning PTS technique with low computational complexity

Algorithm for reducing PAPR of Multicode CDMA using Reed–Muller codes

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