Frequency Modulation

In this paper, we propose an effective AMC using deep learning (DL) for flexible and adaptive OFDM-based optical networks. The proposed DL-based AMC is able to classify four typical modulation schemes such as binary phase-shift keying (BPSK), quadrature PSK (QPSK), 8-PSK, and 16- quadrature amplitude modulation (QAM) in dynamic network conditions.

6p viengfa 28-10-2024 2 1   Download

In this article, we establish a Digital Radio over Fiber (DRoF) information system with two wireless channels utilizing two advanced phase modulation techniques, namely Differential Phase Shift Keying (DPSK), for the CRAN connection and investigate parameters related to nonlinearity such as refractive index n2.

6p viengfa 28-10-2024 2 2   Download

Bài viết này giới thiệu phát triển một bộ thu mềm RTL-SDR cho hệ thống thông tin tương tự sử dụng điều tần (FM - Frequency Modulation). Bộ thu FM RTL-SDR có thể làm việc để thu được tín hiệu FM của các đài phát thanh FM như Hải Phòng, tại tần số 93,7MHz.

6p vimarissamayer 02-06-2022 29 4   Download

Nghiên cứu này đề xuất sử dụng mạng nơ-ron tích chập kết nối chéo (CrossCNN: Cross-connection Convolutional Neural Network) để nhận dạng cử chỉ tay dựa trên dữ liệu phân tích phổ Doppler vi mô (micro-Doppler) của ra-đa FMCW (Frequency Modulated Continuous Wave). Thêm vào đó, các mức nhiễu khác nhau được thêm vào dữ liệu để đánh giá đầy đủ hơn đối với mô hình đề xuất.

8p vibigates 29-10-2021 24 1   Download

In recent years, optical orthogonal frequency division multiplexing (OOFDM) has emerged as a dominant research and development area in the field of high-speed optical communications. OFDM is a potential candidate as the most promising next-generation optical networks such as passive optical networks and optical transport networks, due to their simple configuration based on low cost, high speed data rates, high spectral efficiency, high quality of service and robustness against narrow band interference, frequency selective fading, and chromatic dispersion.

99p nguathienthan12 18-05-2021 21 7   Download

In this work, one of the methods deploying encryption to cipher data is represented. The primary object of this project is applying Advanced Encryption Standard (AES) in communications based Orthogonal Frequency Division Multiplexing (OFDM). This article discusses the security of the method encrypting directly QAM symbols instead of input bit-stream.

8p tamynhan6 14-09-2020 34 3   Download

This thesis has proposed two systems: the RIM-OFDM system with diversity reception exploits simultaneously the frequency and spatial diversity to achieve better SEP performance than the conventional IM-OFDM with diversity reception; The RIM-OFDM system with CI attains higher reliability and flexibility than the conventional IM-OFDM-CI system. The low-complexity detectors were also proposed to reduce the complexity while still achieve nearly same performance of the ML detector.

26p gaocaolon6 30-07-2020 33 3   Download

Sơ đồ điều chế mã có xáo trộn bit (BICM: Bit Interleaved Code Modulation) và Sơ đồ điều chế mã có xáo trộn bit kết hợp với giải mã lặp: BICM-ID (Bit Interleaved Coded Modulation with Iterative Decoding) đã được đề cập nhiều trên các tạp chí có uy tín. Truyền dẫn ghép kênh phân chia theo tần số trực giao (OFDM - Orthogonal Frequency Division Multiplexing) là kỹ thuật cho phép tăng tốc độ truyền dẫn và chống fading rất tốt nên việc kết hợp giữa sơ đồ BICM-ID với OFDM được đánh giá là có tiềm năng. Tuy nhiên trong chuẩn 802.11 chưa áp dụng sơ đồ điều chế này.

8p thithizone 16-07-2019 49 1   Download

Lecture "Radio Communication Circuits: Chapter 7&8" presents the following contents: Analog Modulation Circuits (Amplitude Modulation, Frequency Modulation, Phase Modulation), Digital Modulation Circuits (ASK, FSK, PSK, QPSK, M-ary PSK DPSK, M-ary QAM). Invite you to consult.

39p doinhugiobay_12 15-01-2016 48 4   Download

In this study, the air-plasma generated by radio-frequency was used to treat bamboo fiber. The treatment parameters were studied to find the suitable condition. The testing on tensile strength, tensile modulus, module Weibull and elongation to break of the fiber, the measurement of contact angles and the SEM analysis showed that at the high frequency of 12 kHz, power 50 W and treatment time of 5 minutes, after air-plasma treatment the tensile strength and tensile modulus of bamboo fiber increased more than double (101.1% and 101.

5p uocvong01 24-09-2015 26 6   Download

Tài liệu Radar sóng liên tục điều biến tần số FM - CW (Frequency Modulated Continuous Wave) cung cấp cho các bạn những kiến thức về nguyên lý và hoạt động của Radar sóng liên tục điều biến tần số FM - CW. Mời các bạn tham khảo tài liệu để nắm bắt nội dung chi tiết.

6p buinhubinh 24-03-2015 180 29   Download

PCM consists of three steps to digitize an analog signal: 1.Sampling 2.Quantization 3.Binary encoding Before we sample, we have to filter the signal to limit the maximum frequency of the signal as it affects the sampling rate. Filtering should ensure that we do not distort the signal, ie remove high frequency components that affect the signal shape.

75p vanmanh1008 24-06-2013 49 4   Download

High Frequency Data Link, or HFDL, is part of ARINC’s GLOBALink end-to-end communication system The HFDL system is a segment of the Aircraft Communications Addressing and Reporting System (ACARS) used to exchange Airline Operational Control (AOC) and Air Traffic Control (ATS) messagesbetween aircraft end systems and corresponding ground-based stations. GLOBALink/HF provides HF-based, air-to-ground digital communications with aircraft using ARINC 635 protocol. The HFDL system uses the principles of geographic diversity and frequency diversity to optimize HF propagation...

35p hanampro91 10-05-2013 66 4   Download

Fluorescence ratio imaging indicates that immobilized, aspirin-treated platelets, loaded with Fura-2, respond to inositol 1,4,5-trisphosphate- (InsP3)-generating agonists such as thrombin by high-frequency, irregular rises in cytosolic [Ca 2+ ] i with spikes that vary in peak level and peak-to-peak interval. This differs from the regular [Ca 2+ ] i oscillations observed inother, larger cells.

10p research12 29-04-2013 42 3   Download

FDM Useful bandwidth of medium exceeds required bandwidth of channel Each signal is modulated to a different carrier frequency Carrier frequencies separated so signals do not overlap (guard bands) e.g. broadcast radio Channel allocated even if no data

38p trada85 18-01-2013 57 7   Download

This paper reports experimental results of a radar system design. In the radar transmitter, a 13-bit Barker code with bit duration 3.24 µs and various other codes are generated by the microcontroller PIC16F877A. This code is then used to modulate IF 10.3 MHz to become BPSK signal. A stable local oscillator is also designed by PLL, VCO, and PIC16F877A. The operation frequency range of the oscillator is from 800 MHz to 900

7p tuanlocmuido 19-12-2012 75 2   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Efficient and Robust Detection of GFSK Signals under Dispersive Channel, Modulation Index, and Carrier Frequency Offset Conditions

11p dauphong20 11-03-2012 59 4   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Optimized Irregular Low-Density Parity-Check Codes for Multicarrier Modulations over Frequency-Selective Channels

11p sting12 11-03-2012 39 4   Download

EURASIP Journal on Applied Signal Processing 2003:7, 668–675 c 2003 Hindawi Publishing Corporation Joint Acoustic and Modulation Frequency Les Atlas Department of Electrical Engineering, Box 352500, Seattle, WA 98195-2500, USA Email: atlas@ee.washington.edu Shihab A. Shamma Department of Electrical and Computer Engineering and Center for Auditory and Acoustic Research, Institute for Systems Research, University of Maryland, College Park, MD 20742, USA Email: sas@eng.umd.

8p sting12 10-03-2012 64 5   Download

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article An Approach for Synthesis of Modulated M-Channel FIR Filter Banks Utilizing the Frequency-Response Masking Technique

13p dauphong20 10-03-2012 38 2   Download