Spread space-spectrum multiple access

B. K. Ng, E. S. Sousa

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


In this paper; a new multiple access scheme suitable for the forward link transmission in a multiuser MIMO system is investigated. Unlike traditional MIMO multiple access schemes, which rely on orthogonal-temporal channels (e.g. TDMA), the proposed scheme, namely the spread space-spectrum multiple access (SSSMA), exploits the space-domain for multiuser multiplexing. As its name suggests, SSSMA utilizes the available degrees of freedom offered by the spread-spectrum and those by the multiple transmit antennas to perform multiple access. At the base-station transmitter, each coded data stream corresponding to a unique user-channel is modulated with a user-specific two-dimensional spreading sequence and added together with other channels' modulated signals. At each user's receiver, the multiple-access-interference (MAI) generated from the same base station is mitigated through iterative multiuser detection and decoding. We focus on the performance of SSSMA in two different environments: (1) local point-to-multipoint network such as central access LAN; and (2) a power-controlled cellular system. It is shown that not only does the SSSMA offer near-theoretic-capacity performance in both environments, it is able to exploit a new form of diversity, namely the space-interferers diversity, in an ideal power-controlled network while other MIMO multiple access schemes fail to do so.

Original languageEnglish
Title of host publicationProceedings - 2003 IEEE Radio and Wireless Conference, RAWCON 2003
EditorsGeorge Heiter
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages6
ISBN (Electronic)0780378296, 9780780378292
Publication statusPublished - 2003
Externally publishedYes
Event2003 IEEE Radio and Wireless Conference, RAWCON 2003 - Boston, United States
Duration: 10 Aug 200313 Aug 2003

Publication series

NameProceedings - 2003 IEEE Radio and Wireless Conference, RAWCON 2003


Conference2003 IEEE Radio and Wireless Conference, RAWCON 2003
Country/TerritoryUnited States


  • Base stations
  • Iterative decoding
  • Local area networks
  • MIMO
  • Modulation coding
  • Multiuser detection
  • Spread spectrum communication
  • Time division multiple access
  • Transmitters
  • Transmitting antennas


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