Channel Statistics-Based RF-Pre-Processing with Antenna Selection

Research output: Contribution to journalArticle


We introduce two novel joint radio-frequency (RF)-baseband designs for receivers in a MIMO system with Nt transmit antennas, Nr receive antennas, but only L < Nr RF chains at the receiver. The joint design introduces an RF pre-processing matrix that processes the signals from the different antennas, and is followed by selection (if necessary), down-conversion, and further processing in the baseband. The schemes are similar to conventional antenna selection in that they use fewer RF chains than antenna elements, but achieve superior performance by exploiting the spatial correlation of the received signals. The first of our proposed designs uses an L x Nr RF pre-processing matrix that outputs only L streams followed by baseband signal processing, and, thus, eliminates the need for a selection switch. The second one uses an Nr x Nr RF pre-processing matrix that outputs Nr streams and is followed by a switch that selects L streams for baseband signal processing. Both spatial diversity and spatial multiplexing systems are considered and the optimum pre-processing matrices are derived for all cases. To accommodate practical RF design constraints, which prefer a variable phase-shifter-based implementation, a sub-optimal phase approximation is also introduced. Performance better than conventional antenna selection and close to the full complexity receiver is observed in both single cluster and multi-cluster wireless channels. A beam-pattern-based geometric intuition is also developed to illustrate the effectiveness of the optimal solution.


  • P Sudarshan
  • N B Mehta
  • Andreas Molisch
  • J Zhang
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Electrical Engineering, Electronic Engineering, Information Engineering


  • MIMO systems, antenna arrays, antenna selection, channel statistics, signal to noise ratio, information rates, phase shifters, spatial multiplexing, diversity methods
Original languageEnglish
Pages (from-to)3501-3511
JournalIEEE Transactions on Wireless Communications
Issue number12
Publication statusPublished - 2006
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Department of Electroscience (011041000)