On further reduction of complexity in tree pruning based sphere search

Byonghyo Shim, Insung Kang

Research output: Contribution to journalArticlepeer-review

34 Citations (Scopus)


In this letter, we propose an extension of the probabilistic tree pruning sphere decoding (PTP-SD) algorithm that provides further improvement of the computational complexity with minimal extra cost and negligible performance penalty. In contrast to the PTP-SD that considers the tightening of necessary conditions in the sphere search using per-layer radius adjustment, the proposed method focuses on the sphere radius control strategy when a candidate lattice point is found. For this purpose, the dynamic radius update strategy depending on the lattice point found as well as the lattice independent radius selection scheme are jointly exploited. As a result, while maintaining the effectiveness of the PTP-SD, further reduction of the computational complexity, in particular for high SNR regime, can be achieved. From simulations in multiple-input and multiple-output (MIMO) channels, it is shown that the proposed method provides a considerable improvement in complexity with near-ML performance.

Original languageEnglish
Article number5407602
Pages (from-to)417-422
Number of pages6
JournalIEEE Transactions on Communications
Issue number2
Publication statusPublished - 2010 Feb


  • Maximum likelihood decoding
  • Multiple inputmultiple output
  • Probabilistic tree Pruning
  • Sphere decoding
  • Sphere radius

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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