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  • Research Article
  • Open Access

Maximum-Likelihood Sequence Detection of Multiple Antenna Systems over Dispersive Channels via Sphere Decoding

EURASIP Journal on Advances in Signal Processing20022002:156743

  • Received: 6 May 2001
  • Published:


Multiple antenna systems are capable of providing high data rate transmissions over wireless channels. When the channels are dispersive, the signal at each receive antenna is a combination of both the current and past symbols sent from all transmit antennas corrupted by noise. The optimal receiver is a maximum-likelihood sequence detector and is often considered to be practically infeasible due to high computational complexity (exponential in number of antennas and channel memory). Therefore, in practice, one often settles for a less complex suboptimal receiver structure, typically with an equalizer meant to suppress both the intersymbol and interuser interference, followed by the decoder. We propose a sphere decoding for the sequence detection in multiple antenna communication systems over dispersive channels. The sphere decoding provides the maximum-likelihood estimate with computational complexity comparable to the standard space-time decision-feedback equalizing (DFE) algorithms. The performance and complexity of the sphere decoding are compared with the DFE algorithm by means of simulations.


  • sphere decoding
  • maximum-likelihood
  • multiple antennas
  • dispersive channels
  • computational complexity

Authors’ Affiliations

Information Systems Laboratory, Stanford University, Stanford, CA 94305, USA
Department of Electrical Engineering, California Institute of Technology, Pasadena, CA 91125, USA


© Vikalo and Hassibi 2002