Summary
IEICE Information and Communication Technology Forum
2013
Session Number:COMM2
Session:
Number:COMM2-2
PAPR Reduction and Related Techniques for Power Efficient Multi-Carrier/Multi-Code Wireless Communication Systems
Osamu Muta,
pp.-
Publication Date:2013-07-20
Online ISSN:2188-5079
Summary:
Demands for higher data rate in wireless communication systems have been increasing recently. In general, as transmission rate increases, cell coverage area decreases, and hence it is required to deploy many base nodes as access point (AP) in order to cover the service area, and consequently increase implementation cost of wire-line systems that are connected to each AP. One of solutions to this, a radio relay system such as wireless backhaul is promising, where several APs are connected to a radio relay station (RS) by radio channels and a few of them are connected to the outside network by cable. In this system, at each base station such as APs and RSs, it is desirable to use a power amplifier with high power efficiency and low nonlinear distortion. When the signal is amplified at a power amplifier with nonlinear characteristics, out-of-band radiation is generated attributable to nonlinear distortion. Although nonlinear distortion is reduced by decreasing the signal level to operate the amplifier within linear region, i.e., taking a large amount of back-off from saturation point of power amplifier, it causes power efficiency degradation. Therefore, it is necessary to compensate for nonlinearity of input-output characteristic in power amplifiers in order to satisfy two conflicting requirements, i.e., high power efficiency and low nonlinear distortion.