Walsh-Like Nonlinear Phase Orthogonal Codes for Direct Sequence CDMA Communications

@article{Akansu2007WalshLikeNP,
  title={Walsh-Like Nonlinear Phase Orthogonal Codes for Direct Sequence CDMA Communications},
  author={Ali N. Akansu and Radha Poluri},
  journal={IEEE Transactions on Signal Processing},
  year={2007},
  volume={55},
  pages={3800-3806}
}
  • A. AkansuR. Poluri
  • Published 1 July 2007
  • Computer Science
  • IEEE Transactions on Signal Processing
Walsh codes are perfectly orthogonal binary (antipodal) block codes that found their use in many popular applications over several decades including synchronous multiuser communications. It is well known in the literature that they perform poorly for the case of asynchronous multiuser communications. Therefore, the near-orthogonal and nonlinear phase gold codes with better performance are the preferred user codes in asynchronous direct sequence code division multiple access (DS-CDMA… 

Figures and Tables from this paper

PERFORMANCE ANALYSIS OF NEW BINARY ORTHOGONAL CODES FOR DS-CDMA COMMUNICATION OVER AWGN CHANNEL

This paper has limited its studies to single and two users over AWGN channel in order to work with all popular codes such as Gold, Kasami, Hadamard–Walsh and new orthogonal sequence with an intention of highlighting adaptive nature and increased capacity of new orthogsonal sequence for DS-CDMA.

Varying Power Integer Codes for CDMA Communications

  • R. PoluriA. Akansu
  • Computer Science
    2007 Conference Record of the Forty-First Asilomar Conference on Signals, Systems and Computers
  • 2007
It is predicted that increasing the available spreading code families with various short and long code lengths, and good performance brings more efficiency and security for the design of software radio and dense sensor systems in their future implementations.

Performance Analysis of New Binary User Codes for DS-CDMA Communication

New binary spreading codes through correlation properties are analyzed and their performance over additive white Gaussian noise (AWGN) channel is presented and the auto and cross correlation properties of the proposed codes are compared with those of Walsh codes and gold codes.

Performance analysis of new binary user codes for DS-CDMA communication over Rayleigh fading channel

  • K. UshaK. J. Sankar
  • Computer Science, Business
    2013 Annual International Conference on Emerging Research Areas and 2013 International Conference on Microelectronics, Communications and Renewable Energy
  • 2013
Performance of the proposed binary user codes for both synchronous and asynchronous direct sequence CDMA communication over Rayleigh fading channel is discussed in the current work.

Design and Performance of Spread Spectrum Karhunen–Loeve Transform for Direct Sequence CDMA Communications

The eigen-analysis-based optimal design method of orthogonal block transform, the so-called Karhunen-Loeve transform, is used to generate a new family of spread spectrum codes that might find their application in direct sequence code division multiple access (CDMA) communications.

Continuous Phase Modulation for Multi-Level Spreading Codes in CDMA Communications

It is shown that CPM-DS-CDMA system employing multi-level spreading codes significantly outperform binary spreading codes under the same test conditions.

A New Walsh-Like Near Orthogonal (WNO) Sequence for Asynchronous CDMA System

An innovative attempt to enhance the correlation properties of existing Walsh code through one simple yet powerful algorithm that generates a code of length ‘N’ which makes the code generation algorithm recursive in nature.

BER Performance of Walsh–Hadamard Like Kronecker Product Codes in a DS-CDMA and Cognitive Underlay System

A new set of binary code families similar to Walsh codes are obtained based on the concept of code concatenation and permutation and it is shown that these codes can be generated by reconfiguring the Walsh–Hadamard code generator.

Novel Hybrid Orthogonal Large Set Code Sequence for High Density Wireless Networks

The authors report the design of hybrid orthogonal large set (HOLS) code for synchronous CDMA systems and demonstrate that the BER performance of the HOLS code is comparable to that of the existing Orthogonal codes, but outperforms Gold and large set Kasami code sequences.

A Novel Orthogonal Minimum Correlation Spreading Code in CDMA System

A novel orthogonal spreading code called “Orthogonal Minimum Correlation Spreading Code” (OMCSC) has been proposed which can serve a large number of users and is simultaneously expected to reduce the effect of MAI and ISI.
...

References

SHOWING 1-10 OF 26 REFERENCES

New orthogonal binary user codes for multiuser spread spectrum communications

It is shown in this paper that the proposed binary user code family outperforms the Walsh codes significantly and they match in performance with the popular, nearly orthogonal Gold codes closely for asynchronous multi-user communications.

Optimal spread spectrum sequences-constructed from Gold codes

This paper derives general results on the partial auto-correlation function of the optimal spreading sequences for asynchronous CDMA systems with respect to the minimization of the average error

A new look at digital orthogonal transmultiplexers for CDMA communications

It is shown that the proposed multivalued spread spectrum PR-QMF codes with minimized auto and cross-correlation properties outperform the conventional binary Gold codes in CDMA communication scenarios considered in the article.

Extended orthogonal code designs with applications in CDMA

  • D. GerakoulisS. Ghassemzadeh
  • Computer Science
    2000 IEEE Sixth International Symposium on Spread Spectrum Techniques and Applications. ISSTA 2000. Proceedings (Cat. No.00TH8536)
  • 2000
Methods of generating orthogonal codes are presented and applied in CDMA systems and Kronecker matrix products are presented, which are used in the constructing of codes of all possible lengths up to 256.

Comparison of correlation parameters of binary codes for DS/CDMA systems

An objective way is presented to measure the performance of different codes based on various correlation parameters such as aperiodic, even, odd, maximal, mean and square-sum cross-correlations in a DS/CDMA system.

Digital Communication Over Fading Channels: A Unified Approach to Performance Analysis

The book gives many numerical illustrations expressed in large collections of system performance curves, allowing the researchers or system designers to perform trade-off studies of the average bit error rate and symbol error rate.

Iterative construction of optimum signature sequence sets in synchronous CDMA systems

This work presents an algorithm where users update their transmitter signature sequences sequentially, in a distributed fashion, by using available receiver measurements, and proves that the algorithm converges to a set of orthogonal signature sequences when the number of users is less than or equal to the processing gain.

Spreading codes for direct sequence CDMA and wideband CDMA cellular networks

This article presents an overview of the spreading techniques for use in direct sequence CDMA cellular networks, and describes different methods of multiple spreading for channelization and scrambling in CDMA and W-CDMA realizations.

Orthogonal code design for quasi-synchronous CDMA

A new code design method for quasi-synchronous CDMA is proposed. The proposed scheme, based on the theory of finite projective planes, has the following advantages: orthogonality; low