Channel Equalization of a Signal with Tilted Phase

Nisha Mary Joseph, Amrutha V Nair

Abstract: Orthogonal Frequency Division Multiplexing (OFDM) is closely related to frequency division multiplexing technique but it is a multicarrier modulation technique. In this scheme, there are orthogonal subcarriers that will be closely spaced. These subcarriers are used for carrying data as parallel streams. Hence its said to be a parallel transmission scheme as well. A channel is affected by several factors that can degrade the overall performance of the system. There are certain impairments like Clock Frequency Offset (CFO), Chromatic Dispersion (CD), and polarization Mode Dispersion (PMD). This can cause Common Phase Error (CPE) on the OFDM symbol. This CPE can be compared with the skewed image in image processing domain and algorithm like Minimum Bounding Box (MBB) can be used for its correction. Traditional methods for CPE correction is also simulated and algorithms implemented are Least Mean Square (LMS) and Constant Modulus Algorithm (CMA).

Keywords: Skewed image, CPE, Image processing, MBB, LMS, CMA