Title :
Blind Adaptive Recognition of Different QPSK Modulated Signals for Software Defined Radio Applications
Author :
Naik, M. Vastram ; Bhattacharjee, R. ; Mahanta, A. ; Nemade, H.B.
Author_Institution :
Dept. of Electr. & Commun. Eng., Indian Inst. of Technol., Guwahati
Abstract :
This paper addresses the issue of recognizing and distinguishing among QPSK modulated signal variants such as QPSK, OQPSK and pi/4-DQPSK, from the samples of received noisy and faded PSK signal. The proposed algorithm is based on computation of relative Euclidean distance and relative phase difference among the received symbols in a frame. Constant modulus (CM) equalization is performed prior to recognition. Simulation results show that proposed method can perform recognition task with high accuracy even at low signal to noise ratio (SNR) values and employing reasonably small number of data samples. To the best of our knowledge any method for distinguishing among QPSK variants has not been reported in literature
Keywords :
adaptive modulation; blind equalisers; quadrature phase shift keying; signal sampling; software radio; QPSK modulated signal; blind adaptive recognition; constant modulus equalization; data samples; quadrature phase shift keying; relative Euclidean distance; relative phase difference; software defined radio application; AWGN; Application software; Computational modeling; Digital modulation; Euclidean distance; Mean square error methods; Phase shift keying; Quadrature phase shift keying; Signal to noise ratio; Software radio; Automatic Blind Modulation Recognition (ABMR); Constant Modulus Algorithm (CMA); Mean Square Error power (MSE); Tapped Delay Line filter (TDL); Threshold on Moment (ToM); relative Euclidean distance; relative phase difference;
Conference_Titel :
Communication System Software and Middleware, 2006. Comsware 2006. First International Conference on
Conference_Location :
New Delhi
Print_ISBN :
0-7803-9575-1
DOI :
10.1109/COMSWA.2006.1665163
