Cyclically permutable codes for rapid acquisition in DS-CDMA systems with asynchronous base stations

Sriram, Sharath; Hosur, S.

doi:10.1109/49.909611

Cited by 13 publications

(7 citation statements)

References 8 publications

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“…They have been successfully applied in channel coding [14,19] and to generate cyclically permutable codes (CPC) [7]. CPC's have many applications in communication field: as protocol sequences [5,8,16]; in watermarking systems [9]; in direct sequence code division multiplex (DS-CDMA) [17] and in optical communication systems [4].…”

Section: Introductionmentioning

confidence: 99%

On the cyclic order distribution and partitioning of linear cyclic codes

Bastos

Lemos-Neto

2020

São Paulo J. Math. Sci.

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In this paper, we propose a way to partition any linear cyclic code in its cyclic equivalence classes according to the algebraic structure of the code. Such partition is useful to generate cyclically permutable codes directly from linear cyclic codes. We consider the case where the size of the finite field and the block length of the code are coprimes. Moreover, we present a criterion to construct maximal cyclic order codes.

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Section: Introductionmentioning

confidence: 99%

On the cyclic order distribution and partitioning of linear cyclic codes

Bastos

Lemos-Neto

2020

São Paulo J. Math. Sci.

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“…Second, the threestage cell search process was introduced in [4]. The algorithm was further improved in the second stage as the Cyclically Permutable (CP) code was introduced in [5]- [6]. By using (15, 3) Reed-Solomon (R-S) codes, no codeword is a cyclic shift of another one.…”

Section: Introductionmentioning

confidence: 99%

“…In fact, the probabilities for these conditions are very small, which is verified by the computer simulations. Finally, the frame boundary detection probability FB P is expressed in Repeating the above procedure for 6 P , 5 P and combing all teams, we can obtain the successful frame boundary detection probability as (6).…”

mentioning

confidence: 99%

New Code Synchronization Algorithm for the Secondary Cell-search Stage in WCDMA

Liao

Qiu

Elhakeem

2009

2009 International Conference on Communication Software and Networks

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This paper proposes a new code synchronization algorithm for the secondary cell-search stage in Wideband CDMA systems. Rather than using the Cyclically Permutable (CP) code in the Secondary Synchronization Channel (S-SCH) to simultaneously acquire frame boundary and scrambling code group, the new synchronization algorithm implements the same function with less system complexity. New Secondary Synchronization Codes (SSC) are redesigned by splitting them into two sub-sequences. The counter logic unit and BCH decoder make the new algorithm avoid involved and timecostly Reed-Solomon (RS) code comparisons. Analysis and simulation results show that the synchronization error rate (SER) yielded by the new algorithm in Rayleigh fading channels is close to that of the conventional algorithm in the standard. This new synchronization algorithm reduces system complexities, shortens the mean acquisition time and can be implemented in the slot-based cell-search pipeline.

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“…Additionally, non-binary cyclically permutable codes have applications in direct sequence code division multiple access (DS-CDMA) systems with asynchronous base stations [5].…”

mentioning

confidence: 99%

Cyclically permutable codes specified by roots of generator polynomial

Lemos-Neto

Rocha

2014

Electron. lett.

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A condition is proven on the roots of the generator polynomial of a q-ary cyclic code of block length n which guarantees full cyclic order for all nonzero codewords. For such cyclic codes having n = q m − 1, a theorem is proven which allows to partition the set of all nonzero codewords into cyclic equivalence classes of order n.Introduction: In this Letter, a condition is proven on the roots of the generator polynomial of a linear q-ary cyclic code C of block length n which guarantees full cyclic order for all nonzero codewords, where q is the power of a prime and n is a positive integer which divides q m − 1. For such cyclic codes having n = q m − 1, a theorem is proven which allows a systematic partition of the set of all nonzero codewords of C into cyclic equivalence classes of order n [1]. We refer to this latter result as the separation theorem. The goal of the theory in this Letter is the construction of 'cyclically permutable codes' [2].Binary cyclically permutable codes have many applications as, for example, protocol sequences for the collision channel without feedback [1,3], as well as improving robustness against clipping attacks of watermarking systems [4]. Additionally, non-binary cyclically permutable codes have applications in direct sequence code division multiple access (DS-CDMA) systems with asynchronous base stations [5].In [1], conditions are given that should be obeyed by a construction of a cyclically permutable code. The first condition is that the technique for specifying equivalence classes must be easy to build. The second condition specifies the efficiency of the construction, namely, for a given a q-ary cyclic code with block length n, having q k codewords, the number of distinct cyclic equivalence classes produced should be close to the maximum value of q k /n. A third desirable condition is that the minimum Hamming distance of the cyclically permutable code should approach the maximum possible value for the given code parameters. In the sequel, we show that the proposed approach for generating cyclically permutable codes is easily implementable, and for linear q-ary cyclic codes it is optimal in the sense that the number of cyclic equivalence classes selected is precisely (q k − 1)/n, obtained by removing the allzero codewords because it has cyclic order 1 (see Definition 1).

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Cyclically permutable codes for rapid acquisition in DS-CDMA systems with asynchronous base stations

Cited by 13 publications

References 8 publications

On the cyclic order distribution and partitioning of linear cyclic codes

On the cyclic order distribution and partitioning of linear cyclic codes

New Code Synchronization Algorithm for the Secondary Cell-search Stage in WCDMA

Cyclically permutable codes specified by roots of generator polynomial

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