Exact bit error rate calculations for synchronous MC-CDMA over aRayleigh fading channel

The bit error rate of a synchronous multicarrier code-division multiple-access system operating in a Rayleigh fading channel is calculated based on a moment generating function method, without any assumption on the distribution of multiple access interference. Two closed-form BER expressions are derived. Moreover, the BER can be accurately evaluated by using a Gauss-Chebyshev quadrature rule based numerical approach     

A bit error rate analysis for TCP traffic over parallel free space photonics

Inter-satellite links (ISL) are a useful technology to transmit data to space stations and to communicate between satellites. However, there are serious limitations due to long delays and poor channel performance, resulting in high bit error rates (BER). In this paper, parallel transmission and the scaling of the Transport Control Protocol (TCP) window in free space optics (FSO) communications are analyzed in order to overcome these disadvantages in optical inter-satellite links. Latency and BER are the dominant effects that determine link performance. Thus, a physical, link, network and transport cross-layer analysis for FSO over ISL is presented in this paper. This analysis shows the advantages and disadvantages of using optical parallel transmission and TCP window scaling for free space optical links between stations and satellite constellations. The key contribution of this work is to simulate the effects of the BER and to link the results to packet error rate (PER) to determine the goodput for TCP transmissions by using a cross-layering approach. The results give evidence that wavelength division multiplexing (WDM) can mitigate the effects of long delay and high BER for a FSO communication using TCP.     

一种基于FPGA的高速误码测试仪的设计

误码测试仪是检测通信系统可靠性的重要设备。传统的误码测试仪基于CPLD和CPU协同工作,不仅结构复杂,价格昂贵,而且不方便携带。基于FPGA的高速误码测试仪,采用FPGA来完成控制和测试模块的一体化设计,提高了系统功能扩展性和系统的集成度,使得各个功能模块在不改动硬件电路的情况下可以相应变化。在发送端发送m序列作为测试数据,其测试速率最高可达到155 Mb/s。由于将物理层上的各协议层的功能集中到FPGA内部实现,减少了硬件和软件的设计复杂度,并且缩短了系统的开发的周期,具有可升级的特点。     

基于误码率反馈的自动色散补偿

对40Gbit／s光通信系统的色散容限、Q值和误码率(BER)之间的关系进行了讨论,同时提出了一种基于误码率反馈的色散补偿技术。     

Performance analysis of bit error rate of data link system under pulse LFM interference in time-varying rayleigh channel

Wireless Networks - In such mobile platforms as ships and aircraft, the detection and reconnaissance devices are near to the communication facilities. When working at the same time, they will...     

太阳风湍流强闪烁信道下BPSK误码率闭式近似

由太阳风湍流引起的航天器对地链路上的信号强度波动会降低遥测性能,建立可靠的深空通信链路是至关重要的.文章通过分析太阳风引起的遥测信号幅度闪烁特性,建立了遥测链路太阳风湍流强闪烁信道K分布模型;利用Laguerre正交多项式,完成信道K分布近似,并给出了太阳风湍流强闪烁信道下二进制相移键控(binary phase sh...     

TH-CDMA/PPM的比特误码率分析与研究

对采用二元脉冲位置调制的超宽带跳时多路无线电网络的误码率进行了分析。在矩形脉冲的前提下,可以得到关于TH-CDMA/PPM信号在高斯白噪声信道存在k个干扰时错误比特的概率。通过概率的表达式来评定类高斯噪声的准确性,从而可以对超宽带脉冲无线电网络的类高斯噪声性能进行分析。通过大量的仿真结果可以看到,由类高斯噪声产生的比特误码率要低于高斯噪声产生的。对于每个信息比特有较少的脉冲的系统来说,类高斯噪声所产生的错误就变得非常重要。     

Investigations on bit error performance for video over DAB

The digital audio broadcasting (DAB) system which was originally designed for high quality audio transmission to mobile receivers is investigated for transmission of compressed digital video and multimedia signals. The bit error performance is considered using various levels of error protection provided by the DAB system. As a result, a net bit rate of about 1.5 Mbit/s can be achieved. With additional error correction coding, a bit error ratio (BER) of less than 10^-10 can be realized. This is the requirement for compressed video signals. The SNR per bit is below 16 dB. The results are demonstrated and compared using computer simulations of the complete system     

孔径接收对强海洋湍流DPSK调制的水下光通信系统误码率影响研究

水下光通信（underwater wireless optical communication,UWOC）系统具有宽带宽、高保密等优点,适用于水下通信。然而,水下吸收、散射和湍流效应影响了光束传输,限制了系统在长距离方面的应用。本文探讨了差分相移键控（differential phase-shift-keying, DPSK）调制和孔径接收对在Gamma-Gamma强湍流信道中传输的UWOC系统误码率（bit error rate,BER）的影响。基于Whittaker函数,推导出了系统采用DPSK调制高斯光束在强湍流中传输的BER解析式。仿真观察了系统调制方式、孔径接收直径、传输距离以及四种海洋参数对BER性能的影响。结果表明,采用DPSK和较大尺寸的孔径直径接收可以有效地提高BER性能。同时,系统在均方温度耗散率和温度和盐度波动对海洋湍流贡献的比值较小、动力粘度较大,湍流动能耗散率较大或较小的短距离海洋湍流环境中可以获得较好的通信性能。      

Asymptotic minimum bit error rate property of maximum-likelihood multiuser detection

In multiuser detection, the maximum-likelihood (ML) joint detection method is optimal in the sense that it maximizes the probability of correctly detecting all user symbols. However, it is not known whether the ML detector achieves the minimum bit error rate (BER) for each individual user although the ML detector often exhibits superior BER performance in practice. We prove that under high signal-to-noise ratios, the ML detector approaches the minimum BER.     

Further results on the bit error probabilities of MDPSK over thenonselective Rayleigh fading channel with diversity reception

This paper presents a fundamental approach for deriving the bit error probability of BDPSK and QDPSK over the nonselective Rayleigh fading channel for a receiver with an arbitrary IF filter, and for a fading process with an arbitrary Doppler spectrum with arbitrary Doppler bandwidth. The results generalize those published earlier which were restricted to matched filter reception and to a fading process with a small Doppler bandwidth compared to the symbol rate. This allows the error probability to be studied in the presence of varying degrees of ISI due to the bandlimitation of the received signal by the IF filter, and in the presence of fading fluctuations of various rates. The analytical approach presented is simple, and yet powerful in that it can handle the case of diversity reception. This is a great advantage over the alternative approach of using the distribution of the differential phase of the received signal over a symbol interval. The bit error probability results apply to both conventional BDPSK and QDPSK, as well as π/2-2DPSK and π/4-4DPSK, and allow the irreducible bit error probability as well as the SNR at which this irreducible value sets in to be studied as a function of the Doppler bandwidth and IF filter bandwidth. The computed results are applicable to the design of digital cellular mobile communication systems     

NCFSK bit error rate in the presence of unsynchronised co-channelinterferers

The bit error rate (BER) of binary non-coherent frequency shift keying modulation in the presence of multiple unsynchronised co-channel interferers (UCCIs) and Gaussian noise is investigated. It is found that the BER with UCCIs is generally lower than that with synchronised co-channel interferers (SCCIs). The difference between UCCI and SCCI signal-to-interference ratios required to achieve the same BER performance (<10^-2) increases with the number of interferers     

基于DS2172的误码测试仪的设计

在数字通信工程中,误码率是检验数据传输设备及其信道工作质量的一个主要指标,给出了采用AT89C51单片机结合误码测试器DS2172实现简单误码测试仪的设计.     

Thermal noise and bit error rate limits in nanoscale memories

Analysis of the effects of thermal noise in nanoscale memories is presented. A theoretical analysis of thermal noise is used to predict the number of bit errors per year caused by thermal noise.     

高速率DWDM系统OSNR测试

本文结合当今高速率密集波分复用系统的应用,简要介绍了基于不同技术实现对高速率密集波分复用系统光信噪比测试特点及存在的问题,对光信噪比测试中涉及的测试要求和应用场景进行了相应的说明.     

Approximate average bit error probability for DQPSK over fading channels

The bit error probability (BEP) of DQPSK with Gray coding over an AWGN channel can be computed simply, although it is hard to integrate and derive the average BEP for fading channels. Presented are novel approximations of the average BEP of DQPSK with Gray coding over fading channels. Numerical results show that the novel formulations are quite accurate.     

Multiple-antenna-aided OFDM employing genetic-algorithm-assisted minimum bit error rate multiuser detection

The family of minimum bit error rate (MBER) multiuser detectors (MUD) is capable of outperforming the classic minimum mean-squared error (MMSE) MUD in terms of the achievable bit-error rate (BER) owing to directly minimizing the BER cost function. In this paper, we will invoke genetic algorithms (GAs) for finding the optimum weight vectors of the MBER MUD in the context of multiple-antenna-aided multiuser orthogonal frequency division multiplexing (OFDM) . We will also show that the MBER MUD is capable of supporting more users than the number of receiver antennas available, while outperforming the MMSE MUD.     

无线传感器网络中比特错误率估计方法

由于无线传感器网络中干扰检测的性能依赖于比特错误率(Bit Error Rate,BER)估计的准确性,而现有的比特错误率估计方法或者难以实现,或者准确性差。针对这个问题,本文提出了采用差异化思想来提高比特错误率估计准确度的方法DEE(Differentiated Error Estimation)。其主要是发送方在数据包中插入具有不同估错能力的多级估错位,并随机均匀地分布所有估错位。接收方借助BER与奇偶校验失败概率的理论关系来估计BER。同时,DEE利用BER非均匀分布特征来优化各级估错位的能力,提高出现概率高的BER的估计准确度,以降低平均估计误差。实验结果表明,与现有方法EEC相比,DEE可将估计误差平均减少约44%。当估错冗余较低时,DEE可将估计误差减少约68%。