A variable length code transmission technique on multicode DS/SS systems

Yukitoshi Sanada, Kiyomichi Araki

Research output: Contribution to journalArticle

4 Citations (Scopus)


In this paper, a new variable length code transmission technique utilizing multicode DS/SS is proposed. A common problem associated with the use of variable length codes over wireless channels is loss of synchronization due to bit inversion caused by channel noise. The loss of synchronization produces burst errors in the received source symbols. The proposed system assigns multiple spreading codes to a single user to transmit variable length codes. The number of the spreading codes is equal to the maximum bit length of the codewords. All the bits of the codeword are spread and transmitted at one time by utilizing the assigned multiple spreading codes. Therefore no synchronization of the codeword is required. This paper evaluates the performance of the proposed technique over an AWGN channel and a Rayleigh fading channel. Our results show that the proposed technique improves the symbol error rate (SER) performance by 2-3 dB on the AWGN channel and 10-20 dB on the Rayleigh fading channel as compared with a conventional transmission technique. The source-channel coding suitable for the proposed technique improves the performance by another 15 dB on the Rayleigh fading channel. The proposed transmission technique works even in a low Es/No region.

Original languageEnglish
Pages (from-to)625-635
Number of pages11
JournalIEICE Transactions on Communications
Issue number3
Publication statusPublished - 1998 Jan 1
Externally publishedYes



  • Image transmission
  • Multicode ds/ss
  • Variable length code

ASJC Scopus subject areas

  • Software
  • Computer Networks and Communications
  • Electrical and Electronic Engineering

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