Receiver Cancellation Technique for Nonlinear Power Amplifier Distortion in SDMA-OFDM Systems

• Published in: IEEE transactions on vehicular technology Vol. 56; no. 5; pp. 2499 - 2516
• Main Authors: Gregorio, F., Werner, S., Laakso, T.I., Cousseau, J.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.09.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Cancellation; Channel estimation; Channels; Circuit properties; Communication systems; Distortion; Efficiency; Electric, optical and optoelectronic circuits; Electronic circuits; Electronics; Exact sciences and technology; Frequency division multiplexing; Information, signal and communications theory; Linearity; Multiaccess communication; Multiplexing; Multiuser; Nonlinear distortion; Nonlinearity; OFDM; Orthogonal Frequency Division Multiplexing; orthogonal frequency-division multiplexing (OFDM); power amplifier (PA) nonlinearities cancellation; Power amplifiers; Power efficiency; Radiocommunications; Robustness; Signal and communications theory; Simulation; space-division multiple access (SDMA); Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Transmitters. Receivers; Wireless LAN; Performance evaluation; Wireless LAN; Parameter estimation; Bit error rate; Wireless telecommunication; Peak to average power ratio; Non linear phenomenon; Implementation; power amplifier (PA) nonlinearities cancellation; Channel estimation; space-division multiple access (SDMA); Receiver; Power electronics; Low power; Space division multiple access; Upper bound; Multiuser; Linearity; Telecommunication system; Orthogonal frequency division multiplexing; System simulation; Power amplifier; Non linear effect; Low-power electronics; Non linear distortion; Signal distortion; Comparative study; orthogonal frequency-division multiplexing (OFDM)
• ISSN: 0018-9545; 1939-9359
• DOI: 10.1109/TVT.2007.899965

Space-division multiple access (SDMA) and orthogonal frequency-division multiplexing (OFDM) can be combined to design a robust communications system with increased spectral efficiency and system capacity. This combination is one of the most promising candidates for future wireless local area network implementations. However, one drawback of OFDM systems is the high peak-to-average power ratio, which imposes strong requirements on the linearity of power amplifiers (PAs). Such linearity requirements translate into high back-off that results in low power efficiency. In order to improve power efficiency, a PA nonlinearity cancellation (PANC) technique is introduced in this paper. This technique reduces the nonlinear distortion effects on the received signal. The performance of the new technique is evaluated with simulations, which show significant power efficiency improvements. To obtain meaningful results for comparison purposes, we derive a theoretical upper bound on the bit error rate performance of an SDMA-OFDM system subject to PA nonlinearities. In addition, a novel channel estimation technique that combines frequency- and time-domain channel estimation with PANC is also presented. Simulation results show the robustness of the cancellation method also when channel estimation is included.