Title :
Adaptive blind equalization for QAM modulated signals in the presence of frequency offset
Author :
Niroomand, Mehrdad ; Derakhtian, Mostafa ; Shahimaeen, Assieh ; Gazor, Saeed
Author_Institution :
Sch. of Electr., Shiraz Univ., Shiraz, Iran
Abstract :
In this paper, we present an adaptive blind equalization for the frequency selective channel in the presence of the frequency offset. The adaptive recursions is based on the pseudo Newton method with stochastic gradient algorithm initialization (PNSI). We employ a the second order phase lock loop (PLL) to recover the frequency offset. We introduce a pseudo maximum likelihood (ML) method to estimate the frequency offset. The recovered symbols from these methods are compared by simulations which reveal the superiority of the proposed pseudo ML algorithm.
Keywords :
Newton method; adaptive equalisers; blind equalisers; maximum likelihood estimation; phase locked loops; quadrature amplitude modulation; QAM modulated signals; adaptive blind equalization; adaptive recursions; frequency offset; frequency selective channel; pseudoNewton method; pseudomaximum likelihood method; second order phase lock loop; stochastic gradient algorithm initialization; Blind equalizers; Cost function; Estimation; Frequency estimation; Phase locked loops; Signal to noise ratio;
Conference_Titel :
Systems, Signal Processing and their Applications (WOSSPA), 2011 7th International Workshop on
Conference_Location :
Tipaza
Print_ISBN :
978-1-4577-0689-9
DOI :
10.1109/WOSSPA.2011.5931457