Phase Noise Reduction in WLAN by Applying Wavelet Packet Multiplexing

Abstract

The IEEE 802.11 standards for wireless Local Area Networks (LANs) commercialized as Wi-Fi are deployed in office and home environments. These systems provide data rates up to 1300 Mbps at 5 GHz and 400 Mbps at 2.4 GHz with physical layer based on OFDM and MIMOOFDM. Traditionally, multiplexing in OFDM is realized using static orthogonal waveforms derived from Fourier transforms. The decoding of the data at receiver is based on preserving
orthogonality among the subcarriers. However, there are many transmission impairments which lead to reduction of autocorrelation among subcarriers resulting in interference. The impairments of RF circuits impose a limit on high data rate that a system can achieve. Due to long symbol period, OFDM is sensitive to phase noise of the oscillator resulting in increase of cross correlation among the waveforms used for multiplexing. In this paper, realization of WLAN multiplexing using classical flexible orthogonal wavelet packets to improve the BER performance in the presence of phase noise on AWGN channel is considered. The construction framework to design orthogonal wavelets which are optimized to reduce phase offset error is presented. The designed optimal wavelet bases perform better in the presence of phase noise with additional time complexity.

Cite this Article
Govinda Raju M, Uma BV. Phase Noise Reduction in WLAN by Applying Wavelet
Packet Multiplexing. Journal of Communication Engineering & Systems. 2017; 7(3): 8–15p.