Optimal rate allocation for Group Zero Forcing

Sana Sfar, Lin Dai, Khaled Letaief

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


MIMO systems have been shown to provide significant performance gains over traditional single antennas systems that fall in two categories: diversify and multiplexing rate. A tradeoff between these gains was recently put in evidence and has been quantified with the optimal detection. In this paper, we consider the evaluation of such tradeoff when group detection is applied and particularly when the Group Zero Forcing (GZF) receiver structure is considered. To do so, we will define and evaluate the outage probability per group and derive the tradeoff obtained by each of the groups. The overall system tradeoff will be then given by the minimum group tradeoff performance. Optimal rate allocation will also be proposed so as to maximize GZF tradeoff performance. Comparison for a given group partition, with equal rate allocation will show that optimal rate allocation allows us to both maximize the diversity and the multiplexing rate of GZF. Furthermore, considering a fixed number of antennas, we will find the minimum required number of groups for a given tradeoff level, as well as, the optimal group partition that maximizes the system tradeoff. Numerical results will demonstrate the optimality of this scheme. Significant diversity gains will be put in evidence demonstrating that GZF can efficiently bridge the gap between BLAST and the optimal receiver while offering lower levels of complexity.

Original languageEnglish
Title of host publicationGLOBECOM'04 - IEEE Global Telecommunications Conference
Number of pages5
Publication statusPublished - 2004
Externally publishedYes
EventGLOBECOM'04 - IEEE Global Telecommunications Conference - Dallas, TX, United States
Duration: 29 Nov 20043 Dec 2004


OtherGLOBECOM'04 - IEEE Global Telecommunications Conference
CountryUnited States
CityDallas, TX



  • Channel capacity
  • Channel multivariate statistics distribution
  • Diversity-Multiplexing tradeoff
  • Group detection
  • MIMO systems

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Sfar, S., Dai, L., & Letaief, K. (2004). Optimal rate allocation for Group Zero Forcing. In GLOBECOM'04 - IEEE Global Telecommunications Conference (Vol. 1, pp. 371-375)