相关实验视频
Updated: Jul 11, 2026

07:45
Quasi-light Storage for Optical Data Packets
Published on: February 6, 2014
基于多载波M-ary DCSK系统的修改代码指数调制方案
Bin Yu1,2, Guo-Ping Jiang3, Hua Yang4
1School of Computer Science, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
Entropy (Basel, Switzerland)
|March 28, 2025
概括
一个新的多载波M-ary DCSK系统使用修改的代码索引调制来提高性能. 这种新型的MC-MCIM-MDCSK系统与现有方法相比,显示出更高的比特错误率 (BER).
科学领域:
- 无线通信无线通信
- 信号处理 信号处理
- 信息理论 信息理论
背景情况:
- 数字混沌通信系统需要高效的调制技术.
- 现有的M-ary DCSK系统在性能和效率方面面临挑战.
- 代码索引调制为增强数字通信系统提供了一个有前途的方法.
研究的目的:
- 为多载波M-ary DCSK系统 (MC-MCIM-MDCSK) 提出一个新的修改代码索引调制方案.
- 从理论上分析拟议系统在AWGN和多路径雷利淡化通道中的比特误差率 (BER) 性能.
- 评估MC-MCIM-MDCSK系统的能源效率 (EE),频谱效率 (SE),数据速率和复杂性.
主要方法:
- 一个修改的代码索引调制方案是使用两个正交的Walsh代码实现的,用于M-ary DCSK编码器.
- 理论上的BER表达式是为添加式白色高斯噪声 (AWGN) 和多路径雷利淡化通道衍生出来的.
- 分析和比较包括能源效率,频谱效率,数据速率和复杂性在内的性能指标.
主要成果:
- 拟议的MC-MCIM-MDCSK系统与现有的竞争系统相比,实现了较低的比特错误率 (BER).
- 模拟结果验证了衍生的理论BER表达式.
- 该系统展示了能源效率,频谱效率和数据速率之间的有利平衡.
结论:
- 拟议的MC-MCIM-MDCSK系统为BER性能提供了显著的改善.
- 理论分析和模拟证实了系统在各种通道条件下的有效性.
- 这种先进的调制方案为未来的高性能无线通信系统提供了可行的解决方案.
相关概念视频
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
When proton-coupled carbon-13 spectra are simplified by a broadband proton decoupling technique, structural information about the coupled protons is lost. Distortionless enhancement by polarization transfer (DEPT) is a technique that provides information on the number of hydrogens attached to each carbon in a molecule. While the DEPT experiment utilizes complex pulse sequences, the pulse delay and flip angle are specifically manipulated. The resulting signals have different phases depending on...
¹³C NMR: ¹H–¹³C Decoupling
The probability of having two carbon-13 atoms next to each other is negligible because of the low natural abundance of carbon-13. Consequently, peak splitting due to carbon-carbon spin-spin coupling is not observed in spectra. However, protons up to three sigma bonds away split the carbon signal according to the n+1 rule, resulting in complicated spectra.
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Double Resonance Techniques: Overview
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
Spin decoupling is usually achieved by...
Carrier Generation and Recombination
Carrier generation is the process by which electron-hole pairs (EHPs) are created within the semiconductor. In direct-bandgap semiconductors, such as gallium arsenide (GaAs), this occurs efficiently when energy absorption prompts valence electrons to leap into the conduction band, leaving behind holes.
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
This process is given by the generation rate G and is efficient due to the conservation of momentum between the valence band maximum and conduction band minimum.
Indirect generation involves an...
Design Example: Capacitance Multiplier Circuit
In integrated circuit technology, a capacitance multiplier is often utilized to produce a larger capacitance value when a small physical capacitance falls short. This is achieved by a circuit that multiplies capacitance values by a factor of up to 1000, such that a 10-pF capacitor can replicate the performance of a 100-nF capacitor.
The circuit illustrated in Figure 1 below incorporates two op-amps, with the first operating as a voltage follower and the second acting as an inverting amplifier.
The circuit illustrated in Figure 1 below incorporates two op-amps, with the first operating as a voltage follower and the second acting as an inverting amplifier.
Design Example
The innovation of touch-tone telephony revolutionized the telecommunications industry by replacing the traditional rotary dial with a dual-tone multi-frequency (DTMF) signaling system. This system uses a matrix-style keypad with buttons arranged in four rows and three columns, creating 12 distinct signals each assigned to a pair of frequencies. Each button press results in a simultaneous generation of two sinusoidal tones – one from a low-frequency group (697 to 941 Hz) and one from a...

