OVSF code allocation and two-stage combining method to reduce inter-code interference in OFCDM system

Kazuhiko Hasegawa, Ryuichiro Shimura, Tsutomu Ohno, Naoki Yoshimochi, Iwao Sasase

Research output: Chapter in Book/Report/Conference proceedingConference contribution

4 Citations (Scopus)

Abstract

In this paper, we propose an OVSF code allocation at a base station and a two-stage combining method at a receiver to reduce inter-code interference in OFCDM system. In the proposed OVSF code allocation, OVSF codes which have different ancestor codes are allocated to users. If allocated codes are divided into chips shorter than spreading factor, chips which are produced by each allocated codes are orthogonal. In the two-stage combining method, the allocated code is divided into chips and received symbols are despread using chips. Demodulated symbols are produced from the despreading, multiplied by weights, and combined. The combining method of the proposed scheme has two stages. The rst stage is the despreading, and the second stage is the weight combining. The proposed scheme uses few sub-carriers among which a difference of amplitude levels is small at the despreading, and combines demodulated symbols at the weight combining using suitable weights. Thus, the proposed scheme can reduce inter-code interference. We show that the proposed scheme achieves better BER performance than the conventional scheme by computer simulations.

Original languageEnglish
Title of host publication2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005
Pages2500-2504
Number of pages5
Publication statusPublished - 2005 Dec 1
Event2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005 - Berlin, Germany
Duration: 2005 Sep 112005 Sep 14

Publication series

NameIEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC
Volume4

Other

Other2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005
CountryGermany
CityBerlin
Period05/9/1105/9/14

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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  • Cite this

    Hasegawa, K., Shimura, R., Ohno, T., Yoshimochi, N., & Sasase, I. (2005). OVSF code allocation and two-stage combining method to reduce inter-code interference in OFCDM system. In 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2005 (pp. 2500-2504). [1651893] (IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC; Vol. 4).