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Numerical Aspects of MIMO OFDM PHY Layer Applications on SDR Platforms

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Abstract

IEEE 802.11n compliant receivers are composed of a number of functional blocks, each one with a specific computational complexity and requirements for numerical precision. MIMO preprocessing causes a major part of the computational complexity, since it typically consists of operations like QR decompositions or matrix inversions. Hence, it also demands considerable numerical precision, while other parts of the transceiver, e.g. MIMO equalization or OFDM modulation, need significantly less accuracy. Various publications exist on the issue of ASIC design for MIMO preprocessing. However, the increasing variety of mobile communication standards calls for more flexible platforms, implementing the different standards in software, hence called Software Defined Radios (SDRs). This work focuses on achieving bit error rates (BERs) close to floating-point performance while using the limited fixed-point precision typically available on SDR platforms. To that end, several algorithmic enhancements are described that enable a numerically stable MIMO application even on a 16-bit fixed-point platform. These enhancements are implemented on the maturing P2012 platform by ST Microelectronics as proof-of-concept. Execution time as well as error correction performance are discussed as quality indicators of the implementation.

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Authors and Affiliations

  1. Institute for Communication Technologies and Embedded Systems, RWTH Aachen University, Aachen, Germany

    D. Guenther, T. Kempf & G. Ascheid

Authors
  1. D. Guenther
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  2. T. Kempf
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  3. G. Ascheid
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Corresponding author

Correspondence to D. Guenther.

Additional information

This work has been supported by the UMIC Research Centre, RWTH Aachen University and by the EC under grant 2PARMA FP7-248716.

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Guenther, D., Kempf, T. & Ascheid, G. Numerical Aspects of MIMO OFDM PHY Layer Applications on SDR Platforms. J Sign Process Syst 73, 291–300 (2013). https://doi.org/10.1007/s11265-013-0766-y

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  • DOI: https://doi.org/10.1007/s11265-013-0766-y

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