Information Capacity Approximate Analysis and Calculation with Differential Demodulation Method for π/4-DQPSK Modulation System
Baoming Bai · Journal of Chengdu University of Information Technology · 2011
This paper discusses the π/4-DQPSK system information capacity limitation with differential detection method in the view of Shannon information theory.The speed up information of the system was computed with numerical Entropy estimation calculation,and the capacity curve was figured out with horizontal axis marked in Es/E0 and Eb/N0.Explanations were given for the information capacity threshold effect with π/4-DQPSK differential detection.Then the threshold value was computed out.The capacity curve shows the system performance could not be improved even by decreasing the system spectral efficiency when the signal to noise ratio is under the threshold value.