G. Tong Zhou Hua Qian Lei Ding Raviv Raich On the baseband representation of a bandpass nonlinearity. 2953-2957 2005 53 IEEE Transactions on Signal Processing 8-1 http://dx.doi.org/10.1109/TSP.2005.850383 db/journals/tsp/tsp53.html#ZhouQDR05