Research on Soft Demodulation of Anamorphic PCM/FM Signal under the Condition of Low SNR

2014 ◽  
Vol 532 ◽  
pp. 147-151
Author(s):  
Gang Fu ◽  
Dong Xu Zhu ◽  
Ren Long Li ◽  
Li Ping Wang
Keyword(s):  
Bit Error Rate ◽  
Signal To Noise Ratio ◽  
Joint Detection ◽  
Test Results ◽  
Selective Fading ◽  
Frequency Selective Fading ◽  
Low Snr ◽  
Soft Demodulation ◽  
Symbol Detection ◽  
Demodulation Method

Reentry telemetry channel is a special channel in the process of remote sensing, black barrier and multipath effect will cause the PCM/FM telemetry signal-to-noise ratio and frequency selective fading , even break through the traditional demodulation method of demodulation threshold, led to the bit error rate is greatly increased when aircraft fly through the reentry telemetry channel. Aiming at the problem, a sliding length of 1 more Symbol Detection (Multi - Symbol Detection, MSD) demodulation algorithm is studied: the continuous observations of N element signal and local signal for joint Detection, but each time the MSD sentences a MSD earlier with N - 1 element coincidence. In theory, the algorithm can increase the channel gain about 3 db, the simulation and test results verified the effectiveness of the proposed algorithm.

Study on Multipath Effect under the Environment of PCM/FM Telemetry Soft Demodulation

2014 ◽  
Vol 602-605 ◽  
pp. 2298-2301
Author(s):  
Gang Fu ◽  
Yan Jun Wu ◽  
Ren Long Li ◽  
Li Ping Wang
Keyword(s):  
Detection Method ◽  
Multipath Propagation ◽  
Signal To Noise Ratio ◽  
Wireless Channel ◽  
Test Results ◽  
Low Snr ◽  
Soft Demodulation ◽  
Symbol Detection ◽  
Signal Crosstalk ◽  
Demodulation Method

Because the reentry telemetry wireless channel multipath propagation effects and the effect, channel will introduce transmission time delay dispersion, caused between the PCM/FM telemetry signal crosstalk and signal to noise ratio is too low, significantly increase BER. While traditional demodulation method because the demodulator threshold higher no longer apply. Study the problem, a multiple Symbol Detection method based on sliding strategy (Multi - Symbol Detection, MSD), can effectively overcome the low SNR and inter symbol interference. The simulation and test results verify the effectiveness of the method.

Study of PCM/FM Telemetry Sequence Soft Demodulation

2014 ◽  
Vol 989-994 ◽  
pp. 3922-3925
Author(s):  
Dong Xu Zhu ◽  
Gang Fu ◽  
Yue Feng
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Frequency Discrimination ◽  
Detection Performance ◽  
Low Snr ◽  
Soft Demodulation ◽  
Symbol Detection ◽  
Signal Demodulation ◽  
Demodulation Method

In order to improve the performance of PCM/FM signal demodulation system, this paper studies a kind of Symbol Detection more (Multi-Symbol Detection, MSD) technology. First for PCM/FM in hardware demodulation, a series of problems in the introduction of MSD software demodulation method; Then the MSD demodulation under low SNR synchronous implementation; The algorithm simulation, the results show that the bit error rate of 10-4, detection performance than traditional non-coherent frequency discrimination algorithm can improve the nearly 3 dB, the performance is very ideal.

Research on Soft Demodulation of Telemetry Signal Based on the Orthogonal Complex Baseband Rotating MSD

2014 ◽  
Vol 532 ◽  
pp. 152-156
Author(s):  
Gang Fu ◽  
Dong Xu Zhu ◽  
Qian He ◽  
Ming Xin Kou
Keyword(s):  
Test Results ◽  
Soft Demodulation ◽  
Detection Technology ◽  
Symbol Detection ◽  
Signal Demodulation ◽  
And Performance ◽  
Demodulation Method

For PCM/FM telemetry signal demodulation, compared to traditional demodulation method, multiple Symbol Detection technology (Multi - Symbol Detection, MSD) is an effective method for a lower demodulation threshold.[ For software MSD demodulation in the process of PCM/FM telemetry signal algorithm is too complex and cause a large computation takes longer problem, research based on baseband complex rotating orthogonal MSD soft PCM/FM signal demodulation method, this algorithm can greatly reduce the amount of calculation of MSD and performance with the ordinary MSD are basically identical. The simulation and test results verify the effectiveness of the proposed method.

Study of Reentry Telemetry Signal in the Environment of Soft Demodulation

2014 ◽  
Vol 989-994 ◽  
pp. 3926-3929
Author(s):  
Gang Fu ◽  
Min Tao ◽  
Qian He
Keyword(s):  
Phase Characteristic ◽  
Telemetry System ◽  
Test Results ◽  
Signal Phase ◽  
Signal Noise ◽  
Soft Demodulation ◽  
Symbol Detection ◽  
Detection Software ◽  
Threshold Problem ◽  
Demodulation Method

PCM/FM system is one of the most widely used in the rocket telemetry system. Target spacecraft reentry telemetry telemetry signals in the process of low signal noise ratio (SNR), that the breakthrough tradition demodulation method of demodulation threshold problem, combined with the PCM/FM signal phase characteristic, the research based on a baseband complex rotating orthogonal symbol detection software (MSD) to solve method, and the corresponding synchronization algorithm is applied to ensure the smooth operation of the demodulation. The simulation and test results verified the soft demodulation algorithm can make the demodulation threshold effectively reduce.

Soft Demodulation of PCM/FM Signal Based on MSD Research

2014 ◽  
Vol 556-562 ◽  
pp. 5112-5115
Author(s):  
Gang Fu ◽  
Yan Jun Wu ◽  
Yue Feng
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Detection Performance ◽  
Low Snr ◽  
Soft Demodulation ◽  
Demodulation Method

To improve the performance of the system PCM/FM, this paper used the multi-symbols detection (MSD) technology. Firstly PCM/FM in hardware demodulation in a series of problem, introduces MSD software demodulation method. Then the MSD in low SNR environments of a synchronous implementation. The algorithm simulation indicates that the detection performance than the traditional incoherent algorithm is popularly used increased nearly 3 dB at the bit error rate in 10-4 place. Performance is very ideal.

Research on Soft Demodulation of Telemetry Signal in Reentry Telemetry Environment

2014 ◽  
Vol 543-547 ◽  
pp. 2555-2558
Author(s):  
Gang Fu ◽  
Dong Xu Zhu ◽  
Wen Jian Geng
Keyword(s):  
Phase Characteristic ◽  
Telemetry System ◽  
Test Results ◽  
Signal Phase ◽  
Signal Noise ◽  
Soft Demodulation ◽  
Synchronization Algorithm ◽  
Signal Demodulation ◽  
Demodulation Method ◽  
Target Spacecraft

PCM/FM system is one of the most widely used in the missile and rocket telemetry system. For the problem that the breakthrough tradition demodulation method of demodulation threshold leaded by the telemetry signals low signal noise ratio (SNR) of target spacecraft reentry telemetry environment, a baseband complex rotating orthogonal MSD based soft PCM/FM signal demodulation method is studied combined with the PCM/FM signal phase characteristic. The corresponding synchronization algorithm is applied to ensure the smooth operation of the demodulation. The simulation and test results verify the soft demodulation algorithm can make reduce the demodulation threshold effectively.

The Application of DFT Technology in Soft Demodulation of π/4-DQPSK Signals

2014 ◽  
Vol 644-650 ◽  
pp. 4439-4442
Author(s):  
Yan Jun Wu ◽  
Gang Fu ◽  
Peng Yu
Keyword(s):  
Simple Structure ◽  
Signal To Noise Ratio ◽  
Software Radio ◽  
Stable Region ◽  
Sampling Point ◽  
Receiver Design ◽  
Phase Shift Keying ◽  
Soft Demodulation ◽  
Shift Keying ◽  
Demodulation Method

Presented to the π / 4 differential quaternary phase shift keying signal (π/4-DQPSK) using the discrete Fourier transform (DFT) for software demodulation algorithm in consideration of the actual received waveform into transition to π/4-DQPSK District and stable region, and only the waveform sampling point DFT transform the region stable recovery decision. simulation gives the demodulation method to achieve the same differential demodulation relatively simple structure, and the anti-noise in the signal to noise ratio greater than 3dB better performance than the differential demodulation performance, expected the algorithm is applied π/4-DQPSK software radio receiver design.

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