The National Natural Science Foundation of China(No60572072,60496311);the National High Technology Research and Development Program of China (863Program) (No2006AA01Z264);the National Basic Research Program of China (973Program) (No2007CB310603);the PhD Programs Foundation of Ministry of Educa-tion of China (No20060286016)
The performance loss of an approximately 3 dB signal-to-noise ratio is always paid with conventional differential detection compared to the related coherent detection. A new detection scheme consisting of two steps is...