An All-Digital Signal Demodulation Scheme for High Frequency (HF) QAM Signals

2006 ◽  
Author(s):  
Zhao Yan ◽  
Duan Tiandong ◽  
Wu Suqin
Keyword(s):  
High Frequency ◽  
Digital Signal ◽  
Signal Demodulation

scholarly journals Review on the Millimeter-Wave Generation Techniques Based on Photon Assisted for the RoF Network System

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Jiangnan Xiao ◽  
Chuang Zhao ◽  
Xingxing Feng ◽  
Xu Dong ◽  
Jiangli Zuo ◽  
...  
Keyword(s):  
High Frequency ◽  
Low Cost ◽  
Electronic Devices ◽  
Low Frequency ◽  
Digital Signal ◽  
Development Trend ◽  
Wave Generation ◽  
Communication Link ◽  
Network System ◽  
High Frequency Microwave

With the development trend of wireless and broadband in the communication link and even the whole information industry, the demand of high-frequency microwave bandwidth has been increasing. The RoF network system solves the problem of spectrum congestion in low-frequency band by providing an effective technology for the distribution of high-frequency microwave signals over optical fiber links. However, the traditional mm-wave generation technique is limited by the bandwidth of electronic devices. It is difficult to generate high-frequency and low-phase noise mm-wave signals with pure electrical components. The mm-wave communication technology based on photon assisted can overcome the bandwidth bottleneck of electronic devices and provide the potential for developing the low-cost infrastructure demand of broadband mobile services. This paper will briefly explain the characteristics of the RoF network system and the advantages of high-frequency mm-wave. Then we, respectively, introduce the modulation schemes of RoF mm-wave generation based on photon assisted including directly modulated laser (DML), external modulation, and optical heterodyne. The review mainly focuses on a variety of different mm-wave generation technologies including multifrequency vector mm-wave. Furthermore, we list several approaches to realize the large capacity data transmission techniques and describe the digital signal processing (DSP) algorithm flow in the receiver. In the end, we summarize the RoF network system and look forward to the future.

Heterodyne Digital Control of a High-Frequency Micromechanical Oscillator

2005 ◽  
Vol 128 (3) ◽  
pp. 577-583 ◽  
Author(s):  
Thomas E. Kriewall ◽  
Joseph L. Garbini ◽  
John A. Sidles ◽  
Jonathan P. Jacky
Keyword(s):  
High Frequency ◽  
Digital Control ◽  
Narrow Band ◽  
Band System ◽  
Digital Signal ◽  
Computational Effort ◽  
Pass Band ◽  
Magnetic Resonance Force Microscopy ◽  
Force Microscopy ◽  
Lock In

In this paper we present heterodyne control as a technique for digital feedback control of a high-frequency, narrowband micromechanical oscillator. In this technique, isolated and synchronized hardware downconversion and upconversion components are used in conjunction with digital signal processing (DSP) to control the oscillator. Heterodyne control offers reduced computational effort for the digital control of high-frequency, narrow band system, the reduction of noise outside the pass-band, and the generation of lock-in amplifier signals. We present heterodyne control with design criteria in the context of magnetic resonance force microscopy (MRFM) cantilever control. Finally, we present experimental results of heterodyne control applied to an emulated radio-frequency microcantilever system.

The Application of a New Demodulation Technology in the Telemetry System

2014 ◽  
Vol 989-994 ◽  
pp. 4191-4194
Author(s):  
Min Tao ◽  
Gang Fu ◽  
Guang Zhi Wu
Keyword(s):  
Implementation Process ◽  
Digital Signal ◽  
Single Frequency ◽  
Least Mean Square ◽  
Basic Principles ◽  
Performance Simulation ◽  
Signal Demodulation ◽  
Simulation Results ◽  
Demodulation Method ◽  
Tracking Signal

This paper presents a new PCM / FSK digital signal demodulation method. By using an adaptive least mean square error algorithm consider wave single frequency, the tracking signal, analyzes the envelope of the output signal, demodulate the PCM / FSK signal. This paper introduces the basic principles of this demodulation method and implementation process, analyzes the factors that affect the demodulation performance. Simulation results show that this method is superior to the differential demodulation performance, strong anti-jamming capability, ease of software programming and DSP devices achieve a certain value.

scholarly journals Precise digital demodulation for fiber optic interferometer sensors

2016 ◽  
Vol 41 ◽  
pp. 1660139
Author(s):  
Andrei Medvedev ◽  
Andrei Berezhnoi ◽  
Aleksei Kudryashov ◽  
Leonid Liokumovich
Keyword(s):  
Phase Modulation ◽  
Fiber Optic ◽  
Digital Signal ◽  
Signal Extraction ◽  
Programming Environment ◽  
Trigonometric Functions ◽  
Harmonic Phase ◽  
Signal Demodulation ◽  
Digital Demodulation ◽  
Inverse Trigonometric Functions

Different methods are used in the interferometer sensors for target signal extraction. Digital technologies provide new opportunities for precise signal detection. We have developed the principle of signal demodulation using an additional harmonic phase modulation and digital signal processing. The principle allows implementation of processing algorithms using different ratios between modulation and discretization frequencies. The expressions allowing calculation of the phase difference using the inverse trigonometric functions were derived. The method was realized in LabVIEW programming environment and was demonstrated for various signal shapes.

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