N-shift cross-orthogonal sequences

Suehiro, N.; Hatori, Mitsutoshi

doi:10.1109/18.2615

Cited by 330 publications

(121 citation statements)

References 2 publications

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“…Based on two users, each user is assigned a set of two codes of length N and two transmitting bands. The user kth signal during the two intervals is observed in (11). While the transmitting signals during the odd and even intervals on band m are observed in (12) and (13) respectively.…”

Section: An Actual Implementation Of a Decode-and-forward Cooperativementioning

confidence: 99%

“…The highlighted cooperative algorithm is presented in [9]; it considers a decode-and-forward multiple-access cooperation transmission framework using the complete complementary (CC) code sets. These codes have particular correlation properties [10][11][12]. Along each set, the autocorrelation sum is impulsive.…”

Section: An Actual Implementation Of a Decode-and-forward Cooperativementioning

confidence: 99%

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A New Practical Receiver for a Decode-and-Forward Cooperative Cdma Systems Based on a Blind Î»-Combiner

El-Ganainy¹,

El‐Khamy²

2012

PIER Letters

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Abstract-This paper develops a practical receiver suggested for cooperative systems using decode-and-forward transmission and compares it to the theoretical sub-optimum λ-MRC receiver model. The proposed receiver model adopts a channel blind λ-combiner and employs a practical estimation of the combiner's weight λ that changes adaptively for each received bit. The λ estimation process relies on a dynamic-blind calculation performed on the incoming bit stream using an approximate formula. The accuracy of the estimated values of λ against the numerical (optimum) values is verified by comparing their effects on the performance curves. Next, the performance of the proposed receiver is evaluated against the sub-optimum receiver using the closed-form performance equations then verified using an actual implementation of the decode-and-forward cooperative algorithm. The use of the proposed receiver is shown to have reliable performance under different channel assignments and provides adaptivity to channel variations without complexity or exaggerated signal processing.

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Section: An Actual Implementation Of a Decode-and-forward Cooperativementioning

confidence: 99%

Section: An Actual Implementation Of a Decode-and-forward Cooperativementioning

confidence: 99%

A New Practical Receiver for a Decode-and-Forward Cooperative Cdma Systems Based on a Blind Î»-Combiner

El-Ganainy¹,

El‐Khamy²

2012

PIER Letters

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“…In Fig. 3, it is shown that three different seed codes (a, b and c) effectively lead to three sub-sets of the OC codes, which are sub-sets A, B and C, representing the complete complementary codes [15,16], binary complementary codes and polyphase complementary codes respectively, where A & B & S and C & S. Therefore in principle, by using a series of carefully selected seed codes, we can generate the whole super-set S of the perfect complementary codes, each of which should ensure MAI-free and MI-free operation of a CDMA system. Now let us give a simple example to show step by step how the generation procedure works.…”

Section: Corollarymentioning

confidence: 99%

“…Both Golay and Turyn studied pairs of binary complementary codes whose autocorrelation function is zero for all even shifts except the zero shift. Suehiro [15] extended the concept to generation of so called complete complementary (CC) codes whose autocorrelation function is zero for all even and odd shifts except the zero shift and whose cross-correlation function for any pair is zero for all possible shifts. The work carried out in [15] had paved the way for possible applications of the CC codes in CDMA systems, a possible architecture of which has been proposed and studied in [16].…”

Section: Introductionmentioning

confidence: 99%

The REAL Approach to Generate Orthogonal Complementary Codes for Next Generation CDMA Systems

Chen

2006

IIS

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This paper introduces a new approach to generate the orthogonal complementary (OC) codes suitable for new generation CDMA applications, characterized by isotropic multiple access interference (MAI) free and multipath interference (MI) free properties. The code design methodology proposed in this paper is named as ''Real Environment Adaptation Linearization'' (REAL) approach and it takes into account major impairing factors existing in real applications, such as MAI, MI, asynchronous transmissions and random signs in consecutive symbols. A CDMA system using the generated codes can ensure a truly interference-free operation. Two important facts will be revealed by the analysis given in this paper. First, implementation of an interference-free CDMA will never be possible unless using complementary code sets, such as the OC code sets. In other words, all traditional spreading codes working on an one-code-per-user basis are not useful for implementation of an MAI-free and MIfree CDMA system. Second, to enable the interference-free CDMA operation, the flock size of the OC codes should be made equal to the set size of the codes, implying that a OC code set can support as many users as the flock size of the code set. A systematic search has been carried out to generate the super-set of various OC codes with the help of carefully selected seed codes belonging to distinct sub-sets. This paper will also propose an implementation scheme based on multi-carrier CDMA architecture and its performance is compared by simulations with the ones using traditional spreading codes.

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“…In order to support higher splitting factors and longer transmission distance, several coding schemes have been proposed [19][20][21] . The CCC is a sequence set that contains sets of sequences having ideal autocorrelation and cross-correlation properties [22] . Suppose a collection of m sequence sets, each of which contains n finite length sequences of length l. A sequence of CCC U ðmÞ n can be defined as…”

mentioning

confidence: 99%

Fault monitoring in passive optical network using code division multiplex-based dual-OTDR traces comparison

et al. 2017

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A dual optical time domain reflectometry (OTDR) system, which employs two different continuous waves at the optical line terminal and a pair of fiber Bragg gratings at the end of each optical network unit, is proposed in a time-division multiplexing passive optical network (PON). The proposed scheme accomplishes the fiber fault monitoring by comparing the different wavelength's testing curves. Complete complementary code is utilized to measure multiple wavelength signals simultaneously with only one receiver and to improve the dynamic range of this system. The PON system consisting of 20 km feeding fiber and a 1:16 splitter is investigated by the experiments. The experimental results show that the faulty branch can be successfully identified by using our scheme. What is more, we also demonstrate that our scheme can be applied to the multi-stage PON.

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N-shift cross-orthogonal sequences

Cited by 330 publications

References 2 publications

A New Practical Receiver for a Decode-and-Forward Cooperative Cdma Systems Based on a Blind Î»-Combiner

A New Practical Receiver for a Decode-and-Forward Cooperative Cdma Systems Based on a Blind Î»-Combiner

The REAL Approach to Generate Orthogonal Complementary Codes for Next Generation CDMA Systems

Fault monitoring in passive optical network using code division multiplex-based dual-OTDR traces comparison

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