• 首页
• HFSS教程
• ADS教程
• CST教程
• 射频工程师培训
• 微波仪器操作培训
• 天线设计培训
• 射频专业基础课

Ansoft Designer / Ansys Designer 在线帮助文档：

System Simulator >
System Component Models >
Demodulators >
   PI/4DQPSK Demodulator (DQPSKDEM)       

PI/4DQPSK Demodulator (DQPSKDEM)

Notes

1. This model performs PI/4DQPSK demodulation. The in-phase and quadrature inputs to this model (ri(n) and rq(n), n ³ 0) are assumed to have been modulated by the model PI/4DQPSK.

Since the input to the modulator PI/4DQPSK is assumed to be the symbol values A(n) = 0, 1, 2, 3, n ³ 0, the recovered symbol values at the output of the demodulator B(n) are also 0, 1, 2, 3, for n ³ 0.

Let the received complex (in-phase + quadrature) symbols be r(n) = ri(n) + j rq(n), n ³ 0. The demodulation process is performed as follows for n ³ 0:

B(n) = 0, Re{r(n)r*(n-1)} > 0, Im{r(n)r*(n-1)} > 0

B(n) = 1, Re{r(n)r*(n-1)} < 0, Im{r(n)r*(n-1)} > 0

B(n) = 2, Re{r(n)r*(n-1)} > 0, Im{r(n)r*(n-1)} < 0

B(n) = 3, Re{r(n)r*(n-1)} < 0, Im{r(n)r*(n-1)} < 0

where r*(n-1) is the complex conjugate of r(n-1), and Re{.} and Im{.} denote the real and imaginary operators respectively. The following initial condition is always assumed:

r(-1) = cos(PI/4) + j sin(PI/4)

Netlist Form

DQPSKDEM:Name n1 n2 n3 [Rin1=Val] [Rin2=Val] [Rout=Val]

Netlist Example

DQPSKDEM:1 1 2 3

                HFSS视频教程                                      ADS视频教程                               CST视频教程                           Ansoft Designer 中文教程

      Copyright © 2006 - 2013   微波EDA网, All Rights Reserved    业务联系：mweda@163.com