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.

A Novel Symbol Rate Estimation Algorithm for Phase Modulating Signals in Wireless Communications

2013 ◽  
Vol 443 ◽  
pp. 392-396
Author(s):  
Peng Zhou ◽  
Chi Sheng Li
Keyword(s):  
Signal To Noise Ratio ◽  
Estimation Algorithm ◽  
Frequency Resolution ◽  
Phase Shift Keying ◽  
Phase Jump ◽  
Rate Estimation ◽  
Awgn Channel ◽  
Symbol Rate ◽  
Shift Keying ◽  
Simulation Results

In this paper, we proposed a new symbol rate estimation algorithm for phase shift keying (PSK) and qua drawtube amplitude modulation (QAM) signals in AWGN channel First we constructe a delay-multiplied signal, from which we obtaine the modulated information. Then we calculated the instantaneous autocorrelation of the delay-multiplied signal to pick out the phase jump. To eliminate the restriction of frequency resolution in fast Fourier transform, we performed a Chirp-Z transform to find out the exact spectral line which represente the symbol rate of the signal to be analyzed. Compared with the existing algorithms, it is a simple solution that has a better performance and accuracy in low signal-to-noise-ratio channel conditions. Simulation results show that the probability of relative estimating deviation below 0.1% reaches 100% and the average and standard variance of absolute estimation deviation are at the magnitude of 10-2 when SNR is over 2dB.

A Novel Delay-Based GFSK Demodulator in 65 nm CMOS for Low Power Biomedical Applications

2018 ◽  
Vol 10 (3) ◽  
pp. 21-32
Author(s):  
Meng Fu ◽  
Stan Skafidas ◽  
Iven Mareels
Keyword(s):  
Low Power ◽  
Biomedical Applications ◽  
Signal To Noise Ratio ◽  
Electronic Devices ◽  
Silicon Area ◽  
Novel Structure ◽  
Channel Bandwidth ◽  
Shift Keying ◽  
Mics Band ◽  
Demodulation Method

This article describes how, in recent years, with the development of microelectronics, implantable electronic devices have been playing a significant role in modem medicine. Examples of such electronic implant devices are, for instance, retinal prosthesis and brain implants. It brings great challenges in low power radio frequency (RF) and analog designs. This article presents a low power Gaussian frequency shift keying (GFSK) demodulator designed for Medical Implant Communications Service (MICS) band Receiver. This demodulator utilizes a novel structure that a wide IF range can be handled and presents the smallest Δf/f ratio in any published GFSK demodulators. In theory the demodulation method can be applied to any RF frequency. The demodulator draws 550uA from a 1 V power supply. A maximum data rate of 400 Kbits/s can be achieved within the 300 KHz channel bandwidth defined by MICS. A simulated signal-to-noise ratio (SNR) of 15.2dB at AWGN channel is obtained to achieve 10-3 bit error rate (BER). This demodulator is fabricated on 65-nm CMOS and occupies 0.12mm2 silicon area.

scholarly journals A Combinatorial Approach to Evaluation of Reliability of the Receiver Output for BPSK Modulation with Spatial Diversity

10.37236/1028 ◽  
2006 ◽  
Vol 13 (1) ◽  
Author(s):  
S. Bliudze ◽  
D. Krob
Keyword(s):  
Symmetric Functions ◽  
Natural Extension ◽  
Schur Functions ◽  
Digital Signal ◽  
Spatial Diversity ◽  
Phase Shift Keying ◽  
Soft Demodulation ◽  
Shift Keying ◽  
Binary Phase Shift Keying ◽  
Bpsk Modulation

In the context of soft demodulation of a digital signal modulated with Binary Phase Shift Keying (BPSK) technique and in presence of spatial diversity, we show how the theory of symmetric functions can be used to compute the probability that the log-likelihood of a recieved bit is less than a given threshold $\varepsilon$. We show how such computation can be reduced to computing the probability that $U-V < \varepsilon$ (denoted $P(U-V < \varepsilon)$) where $U$ and $V$ are two real random variables such that $U=\sum_{i=1}^N |u_i|^2$ and $V=\sum_{i=1}^N |v_i|^2$ where the $u_i$'s and $v_i$'s are independent centered complex Gaussian variables with variances ${\Bbb E}[\,|u_i|^2\,]=\chi_i$ and ${\Bbb E}[\,|v_i|^2\,]=\delta_i$. We give two expressions in terms of symmetric functions over the alphabets $\Delta=(\delta_1,\dots,\delta_N)$ and $X=(\chi_1,\dots,\chi_N)$ for the first $2N-1$ coefficients of the Taylor expansion of $P(U-V < \varepsilon)$ in terms of $\varepsilon$. The first one is a quotient of multi-Schur functions involving two alphabets derived from alphabets $\Delta$ and $X$, which allows us to give an efficient algorithm for the computation of these coefficients. The second expression involves a certain sum of pairs of Schur functions $s_\lambda(\Delta)$ and $s_\mu(X)$ where $\lambda$ and $\mu$ are complementary shapes inside a $N\times N$ rectangle. We show that such a sum has a natural combinatorial interpretation in terms of what we call square tabloids with ribbons and that there is a natural extension of the Knuth correspondence that associates a (0,1)-matrix to each square tabloid with ribbon. We then show that we can completely characterise the (0,1)-matrices that arise from square tabloids with ribbons under this correspondence.

4PSK Signal Based on FPGA

2013 ◽  
Vol 694-697 ◽  
pp. 2870-2873
Author(s):  
Dong Ming Lei ◽  
Ping Li ◽  
Nian Yu Zou
Keyword(s):  
Phase Shift ◽  
Phase Shift Keying ◽  
Development Environment ◽  
Modulation And Demodulation ◽  
Shift Keying ◽  
Simulation Results ◽  
Demodulation Method

Based on the traditional demodulation method of four phase shift keying (QPSK), a QPSK demodulation model was proposed. The FPGA-based QPSK modulation and demodulation system and circuit had been achieved. In Xilinx ISE12.3 development environment, using the SPARTAN-3E development board, the simulation results demonstrate the feasibility of this design.

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.

Automatic Modulation Identification of MPSK Signals Using Differential Signal and its Higher Order Cumulants

2011 ◽  
Vol 403-408 ◽  
pp. 2547-2551
Author(s):  
Zhan Hui Cai ◽  
Yuan Cheng Yao
Keyword(s):  
Signal To Noise Ratio ◽  
Modulation Classification ◽  
Phase Shift Keying ◽  
Eighth Order ◽  
Differential Signal ◽  
Automatic Modulation Classification ◽  
Shift Keying ◽  
Simulation Results ◽  
Intelligent Communication ◽  
Classification Probability

Automatic modulation classification plays a significant role in intelligent communication. A new method based on feature extraction is proposed for the recognition of M-ary Phase Shift Keying (MPSK) signals. As features, fourth and eighth order cumulants of the input samples and phase differential sequences were applied. It is shown that the cumulant-based features have robust anti-noise ability. Simulation results demonstrate that the correct classification probability (Pcc) with the proposed algorithm is higher than the existing approaches at low signal-to-noise ratio (SNR).

scholarly journals VISUALISASI SISTEM ASYMMETRIC DIGITAL SUBSCRIBER LINE (ADSL) DENGAN MENGGUNAKAN MODULASI QUADRATURE PHASE SHIFT KEYING (QPSK)

2016 ◽  
Vol 3 (1) ◽  
pp. 1-6
Author(s):  
Ahmat Sobri ◽  
Irwan Dinata ◽  
Rudy Kurniawan
Keyword(s):  
Phase Shift ◽  
Gaussian Noise ◽  
Signal To Noise Ratio ◽  
Phase Shift Keying ◽  
Digital Subscriber Line ◽  
Asymmetric Digital Subscriber Line ◽  
Subscriber Line ◽  
Quadrature Phase Shift Keying ◽  
Quadrature Phase ◽  
Shift Keying

Sistem Asymmetric Digital Subscriber Line (ADSL) merupakan teknologi akses yang memungkinkan terjadinya komunikasi data, suara dan video secara bersamaan pada media akses tembaga. Komunikasi data tidak dapat dihindarkan dari adanya derau, tidak terkecuali sistem ADSL yang mengalami kesalahan dalam hal pengiriman yang disebabkan adanya derau sehingga membuat nilai bit error rate (BER) meningkat. Oleh karena itu, diperlukan cara untuk mengurangi derau sehingga dapat memperkecil nilai BER. Untuk mengurangi derau dan mendapatkan nilai BER maka diperlukan metode modulasi Quadrature phase shift keying (QPSK) pada sistem ADSL. Visualisasi sistem dibutuhkan untuk mengetahui kinerja dari sistem ADSL dan mengetahui BER yang di timbulkan. Dari hasil visualisasi dengan memberikan masukan data 64 bit, menampilkan konstelasi yang mengalami penyebaran data tetapi tidak merusak bentuk dari konstelasi. Ketika konstelasi masuk ke kanal Additif White Gaussian Noise (AWGN) dengan simpangan antara 0 dB – 20 dB dan interval 2 dB, dihasilkan nilai BER 0.3906 pada saat Signal to Noise Ratio (SNR) bernilai 0 dB sampai akhirnya BER bernilai nol pada saat SNR berkisar antara 9 dB - 20 dB.

scholarly journals SDPSK-Specific Demodulation Method for the Nanortu Field-Programmable Gate Array / SDPSK-Specifiska Demodulācijas Metode Nanortutm Programmētajām Loģiskajām Integrācijas Shēmām

2013 ◽  
Vol 50 (1) ◽  
pp. 84-90
Author(s):  
A. Skorodumovs
Keyword(s):  
Software Defined Radio ◽  
Phase Shift Keying ◽  
Differential Phase Shift ◽  
Differential Phase Shift Keying ◽  
The Earth ◽  
Shift Keying ◽  
Field Programmable ◽  
Satellite Applications ◽  
Signal Demodulation ◽  
Demodulation Method

The software-defined radio (SDR) solutions inpart flexibility to the satellite applications when the devices are physically inaccessible after the launch. The nanoRTU FPGA-based controller (AAC Microtec) may be programmed to serve as a software-defined differential phase shift keying (SDPSK) modem backend to be used in satellites for communication with the Earth. The modem consists of two units - a modulator and a demodulator. A fully functional symmetric SDPSK modulator for nanoRTU FPGA has already been implemented. The next step of the modem implementation is the development of demodulator. In order to implement such facilities, the existing demodulation techniques should be reviewed in order to propose the appropriate method in which the demodulator would be capable of demodulating a signal, and, at the same time, would be resource-efficient. The author describes a valid method of specific SDPSK signal demodulation for the nanoRTU FPGA.

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