Very efficient frequency usage system using convolutional spread time signals based on complete complementary code

In this article, we present a comprehensive survey of existing literature in the area of complementary coded CDMA (CC-CDMA) technique for wireless communications to provide an introduction and overview to the field. According to the kinds of independent sub-channels, we divide the existing CC-CDMA solutions into two categories: time division multiplex (TDM) and frequency division multiplex (FDM) CC-CDMA systems. Then we compared them in terms of resistance of multiuser interference and multi-path interference, implementation complexity and spread and spectrum efficiency.

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“…One solution to enhance the spectral efficiency is to use convolution operation instead of the direct spreading [8], as shown in Fig. 2.…”

Section: A Tdm Cc-cdma Systemsmentioning

confidence: 99%

A survey of two kinds of complementary coded CDMA wireless communications

Sun

Han

et al. 2014

2014 IEEE Global Communications Conference

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“…Complete complementary codes can be applied into the communication systems such as AS-CDMA [9], [10]. In the AS-CDMA systems using complete complementary codes, both of the co-channel interference and the multipath-fading can be avoided and quite a high frequency usage ratio can be achieved.…”

Section: A Analogy To Communication Schemesmentioning

confidence: 99%

“…Complete complementary codes are employed in various communication systems such as approximately synchronized code division multiple access (AS-CDMA) systems [9], [10] and convolutedtime CDMA (CT-CDMA) [11]. In CT-CDMA system, different user's information data are overlapped and transmitted.…”

Section: Introductionmentioning

confidence: 99%

A blind digital watermarking scheme based on complete complementary codes

Kojima

Ohtani

Matsumoto

et al. 2011

2011 Australian Communications Theory Workshop

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Complete complementary code can be applied to digital watermarking technologies as well as communication systems like approximately synchronized CDMA because of its good correlation properties. In this paper, we propose a blind watermarking algorithm which does not need to refer any original data in the watermark extraction process. We also discuss the analogy between the proposed watermarking scheme and CT-CDMA communication systems based on complete complementary codes. In addition, some extensions of the proposed watermarking method and future problems are discussed in the paper.

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“…In order to avoid the effect of interference on a pilot, for example, a frequency division modulation with two comb-form spectra can be used to transmit pilots and data symbols, where the pilot channel is shared by all users in a time division manner [24,25]. Each user's pilot and data can also be transmitted in a code division manner on a comb-form spectrum that is different from that of the other users [20][21][22][26][27][28][29]. On the other hand, exclusively separated time slots can be allocated to all pilot channels, and a data channel can be shared by all users [23].…”

Section: Signal Detection Principle Based On Pilotsmentioning

confidence: 99%

A multi‐user CDMA receiver utilizing decorrelating detector with additional dummy pilot response

Tomita¹,

Kuroyanagi²,

Ozawa³

et al. 2003

Int J Communication

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SUMMARYA pilot assisted CDMA system which uses extended spreading sequences with guard sequences under a quasi-synchronous condition is capable of separating the interference components included in the input of a de-correlating receiver by solving a system of linear equations. The performance of such a system, however, depends on the property of the de-correlating matrix consisting of the received pilots, which correspond to the respective user spreading sequences and the multi-path channel conditions. That is, the regularity of the matrix often tends to degrade, and the rank reduces occasionally primarily due to the multi-paths, resulting in solutions that are vulnerable to AWGN. The present paper proposes an effective technique to solve this problem by introducing a virtual user into a group of real users that are to be served. The simulation results indicate a remarkable improvement in the bit-error-rate (BER) performance. In addition, based on the BER performance, the system has a RAKE-like function that has power-sum characteristics.

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Very efficient frequency usage system using convolutional spread time signals based on complete complementary code

Cited by 52 publications

References 6 publications

A survey of two kinds of complementary coded CDMA wireless communications

A survey of two kinds of complementary coded CDMA wireless communications

A blind digital watermarking scheme based on complete complementary codes

A multi‐user CDMA receiver utilizing decorrelating detector with additional dummy pilot response

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