Energy Efficient Peak Power Reduction in OFDM with Amplitude Predistortion Aided by Orthogonal Pilots Articles uri icon

publication date

  • February 2013

start page

  • 45

end page

  • 53

issue

  • 1

volume

  • 59

International Standard Serial Number (ISSN)

  • 0098-3063

Electronic International Standard Serial Number (EISSN)

  • 1558-4127

abstract

  • The high Peak-to-Average Power Ratio (PAPR) is a main drawback of Orthogonal Frequency Division Multiplexing (OFDM) systems. We propose a two-step technique to reduce the PAPR consisting of a metric-based constellation extension method, such as Simple Amplitude Predistortion (SAP) algorithm, aided by Orthogonal Pilot Sequences (OPS) in a previous step, where we also provide a low-complex implementation of OPS scheme. We show that our proposal, named OP-SAP, outperforms previous approaches in terms of PAPR reduction, due to joining the benefits of Orthogonal Pilots with SAP algorithm. Moreover, it is energy efficient within two aspects: transmitted energy and implementation energy. OP-SAP saves up to 57% of transmitted energy per predistorted symbol compared to SAP. Regarding implementation energy, PAPR reduction techniques introduce some additional computational complexity, which requires extra cycles in the processor that demand energy consumption. We present an exhaustive analysis on computational power cost that shows the low power consumption of OP-SAP compared to other methods as SeLected Mapping (SLM), what yields a remarkable energy saving in its practical implementation(1).

keywords

  • ofdm; peak to average power ratio; energy efficiency; computational complexity