Hybrid Access Network Integrated With Wireless Multilevel Vector and Wired Baseband Signals Using Frequency Doubling and No Optical Filtering

This letter experimentally demonstrated a hybrid access network which supports both radio-over-fiber and fiber-to-the-x systems. A 20-GHz radio-frequency (RF) 312.5-MSymbol/s M-ary phase-shift keying (PSK) signal and a baseband (BB) 1.25-Gb/s on–off keying signal are simultaneously generated and transmitted over an identical distributed infrastructure. The wired BB signal is compatible with the existing passive optical network (PON) system, and the wireless RF PSK signal can also share the same distributed infrastructure. The proposed system has no RF fading issue, no narrowband optical filter at remote node to separate the RF and BB signals, and can carry vector signals. Moreover, a frequency doubling for optical RF signal generation is achieved to reduce the bandwidth requirement of the transmitter. After transmission over 25-km standard signal-mode fiber, the receiver sensitivity penalties are less than 0.5 dB for both the RF and BB channels.      

Simultaneous Transmission of Wireless and Wireline Services Using a Single 60-GHz Radio-Over-Fiber Channel by Coherent Subcarrier Modulation

We proposed and experimentally demonstrated a novel hybrid subcarrier modulation (H-SCM) technique to generate a spectral-efficient 60-GHz optical millimeter-wave (mm-wave) that carries independent 2.5-Gb/s wireless and 10-Gb/s wireline signals using intensity and phase modulation, respectively. The frequency beating components of the 60-GHz channel due to interleaved and imbalanced optical path in H-SCM are numerically analyzed and experimentally measured in terms of timing jitter and amplitude fluctuation. The generated 60-GHz optical mm-wave signal using H-SCM with phase noise variance of about 0.5 is demonstrated in a radio-over-fiber testbed propagating through a combined distance of 25-km fiber and 4-m free space. The power penalties for the received wireless and wireline signals are 1 and 0.2 dB at $10^{-9}$ bit-error rate, respectively.      

基于EPON＋EOC的三网融合接入系统研究

三网融合推动着接入网向大容量方向发展。本文以低成本、全业务、宽带化的下一代接入网为研究对象,旨在研究光接入网与有线电视同轴电缆网的融合。对基于PON＋EOC的三网融合接入系统进行了研究,提出了＂基于EPON＋高频有源EOC＂的方案。研究目标在于通过综合的拓扑结构和传输技术,实现接入网覆盖范围和容量的拓展并最终实现＂最后一公里＂无缝接入。     

Demodulation Method for Continuous Phase Modulation Signals Based on Least-Squares Method

Continuous phase modulation (CPM) schemes are attractive for telecommunication systems, which are limited in terms of the bandwidth and signal power due to their high spectral efficiency. In this paper we present a method for the demodulation of continuous phase modulation signals based on least-squares method (LSM). This method (CPM-LSM) is based on the optimal linear estimation of information symbols from the phase of the received signal by solving the overdetermined system of equations using the least squares method. Mathematical substantiation for the application of the proposed CPM-LSM method is presented. Preliminary experimental results of modeling using Geo-Mobile Radio (GMR-2) signals indicate that the method is robust with respect to carrier phase errors. Another feature of CPM-LSM method is that it does not use unique words (symbol patterns for amplitude/phase alignment). The latter fact is very important since unique words usually occupy up to twenty percent of transmitted packet size. The absence of unique words can substantially increase the information throughput.     

基于基带噪声互相关法的同源多路信号相位差测量

根据同一激励源信号通过功分器得到的同源多路信号间表现为纯时延的特性,本测量方法对仅存在时延差异的同源多路噪声调频信号进行自相关运算和互相关运算,再根据相关运算得到的不同谱峰位置计算出信号间的相对时延,也就是信号间的相位差。信号间相位差的计算精度与采样频率、采样时间、调频指数有关。随着上述3个参数值的增大,相位差的测量精度增加。     

Low-Cost Transparent Radio-Over-Fiber System for In-Building Distribution of UWB Signals

This paper investigates hybrid fiber-radio networks for in-building distribution of ultrawideband (UWB) signals, in order to extend UWB radio coverage area. An original multipoint to multipoint UWB-over-fiber system, proposed in the frame of BILBAO project, is presented and discussed. System link gain and noise figure are evaluated through theoretical analysis. A simulation model is used to study the impact of E/O transceivers nonlinearity on UWB signals. Experimental results show good agreement with simulation results. A high data rate file transfer, with UWB radio propagation and transmission over 100 m of multimode fiber, has been also successfully demonstrated.      

一种CPM信号与PSK类信号的调制识别算法

提出了一种基于分形盒维数及二次方谱特征的方法,对由CPM与PSK类信号组成的信号集进行调制识别分类。首先提取信号集内各待识别信号的分形盒维数特征,将CPM和OQPSK识别出来;然后对信号集中剩余信号提取相应的二次方谱离散谱线特征依次区分出BPSK、UQPSK和QPSK;最后根据决策树原理设计分类器,实现信号集内信号的识别。仿真结果表明,该算法对信号集内的信号在信噪比达到3 d B以上条件下正确识别率可达到90%以上。     

基于串行RapidIO协议的无线通信基带处理系统架构

基于RapidIO协议提出了一种全新的可扩展的无线通信基带处理系统架构方案.通过与现有架构方案的比较,方案在数据传输、灵活可移植性、布局布线等方面具有突出优势.实验验证了该架构的正确性和合理性,而且该架构具有很强的实用价值.     

模拟信号的数字化无线调制解调

以MCS-51系列单片机为核心，采用D／A转换器TLC5618，A／D转换器MAX197、无线数传模块PTR2000设计了一个模拟信号的数字化无线调翻解调系统。     

关于机场光纤通信运用的讨论

介绍光纤接入网的概念,阐述光接入网在通信网中的重要性和发展趋势,以及光接入网各种网络拓扑结构,提出了选择光接入网网络结构的根据,并进一步讨论了民航机场有线通信中光接入网的实施及构想.     

无线光通信中的脉冲位置宽度调制技术

针对无线光通信系统中L级脉冲位置调制(PPM)技术带宽效率较低的问题,结合L级脉冲位置调制技术和L级脉冲宽度调制(PWM)技术,提出了L级脉冲位置宽度调制(PPWM)技术.该调制技术通过适当降低功率效率提高了带宽效率,分析了PPWM技术的功率效率和带宽效率,在弱湍流信道模型下分析了PPWM调制技术的误包率,并与其他调制技术进行了比较.结果表明L级脉冲位置宽度调制技术具有低误码率,高功率效率、高带宽效率和较低误包率等优点.     

Multisideband Detection Radio-Over-Fiber Link With Phase Modulation and Fiber Demodulation for Vector Signal Transmission

We propose and demonstrate a multisideband detection (MSD) radio-over-fiber (RoF) link with optical phase modulation (PM) and fiber demodulation to transmit vector signals. In the scheme, the optical PM signal is demodulated by the fiber dispersion. The fading effect can be almost entirely overcome thanks to the MSD. In case of 50-Msymbols/s vector signal with frequencies of subcarrier ranging from 2 to 12 GHz over 25-, 50-, and 100-km single-mode fibers, respectively, the RoF-link's error vector magnitude of better than 4.5% and spurious-free dynamic range of more than 97 ${hbox {dB}}cdot hbox{Hz}^{2/3}$ are obtained experimentally.      

A Super-Tripling Technology Used in Radio-Over-Fiber Systems for Multiservice Wireless Signals Within a Millimeter-Wave Band

A super-tripling technology used in radio-over-fiber systems is presented in this letter for the optical generation and multiplexing of multiservice wireless signals within a millimeter-wave band. To realize the technology, optical carrier suppression is followed by optical single sideband with suppressed carrier modulation in the central station and optical stopband filtering in the base station is utilized. With the technology, 38.5-GHz amplitude shift keying and 41-GHz differential phase-shift keying signals both with 1.25-Gb/s data bit rate were demonstrated experimentally, and power penalties of about 1 dB at a bit-error rate of $10^{-8}$ were obtained after both signals transmitted over 10 km fiber. The spurious-free dynamic range of the link was measured to be 65 $hbox{dB}cdothbox{Hz}^{2/3}$ for the 38.5-GHz channel and 70 $hbox{dB}cdothbox{Hz}^{2/3}$ for the 41-GHz channel, both with the phase-noise at about ${-}$70 dBc/Hz.      

A Radio-Over-Fiber Downstream Link Employing Carrier-Suppressed Modulation Scheme to Regenerate and Transmit Vector Signals

In this letter, the optical carrier-suppressed (OCS) modulation scheme is employed to transmit vector signals in radio-over-fiber systems. The proposed architecture employing the OCS modulation scheme needs only a balanced single driven Mach-Zehnder optical modulator, and has advantages of dispersion immunity and doubled frequency. Both detailed theoretical analysis and experiments are presented to demonstrate the feasibility of the proposed architecture.     

无线光通信调制方式研究

大气无线光通信的调制方式有多种,但缺少综合的分析。研究分析了OOK（开关键控）,PPM（脉冲位置调制）,DPIM（数字脉冲间隔调制）和DH—PIM（双头脉冲位置调制）等调制方式的符号结构,发射功率,带宽需求和误时隙率。通过分析可知DPIM和DH—PIM调制方式比较适合作为未来大气无线光通信的调制方式。为无线光通信调制方式的选取提供一定的参考依据并指出其发展趋势。     

基于三值系统的数字相位调制

介绍一种新的应用于三值系统的九相相移键控信号,并讨论了实现三值数字相位调制的一种方法,为用于三值ＣＤＭＡ通信新体制打下了必要的基础。     

基于Rimoldi分解的连续相位调制信号Turbo频域均衡算法

针对高阶部分响应连续相位调制(CPM)信号均衡中存在的复杂度高和性能较差等问题,该文从Rimoldi分解的角度出发,设计了一种新的适用于倾斜相位CPM信号的发射帧结构,并在此基础上结合单载波频域均衡(FDE)和Turbo均衡的思想,提出了一种适用于高阶CPM信号的Turbo频域均衡算法。该算法通过将信号均衡转化到频域进行处理,避免了时域均衡算法在计算均衡器系数时存在的大矩阵求逆问题,同时使用Turbo均衡的软信息迭代处理来改善系统的性能。理论分析和仿真结果表明,对于四阶部分响应CPM信号,在存在严重符号间干扰的多径衰落信道的条件下,该算法与现有的基于符号的频域均衡算法相比,在保持较低复杂度的同时,具有大约1.5 dB的性能增益。     

基于电力线通信的无线接入设备设计

该文介绍了一种用采用ATMEL公司的AT76C510的单芯片IEEE 802.11b基带控制器与电力线载波芯片ST7538构成的低压电力线载波通信无线接入设备的设计方案,详细介绍了该系统的工作原理和软硬件组成。经实际测试证明,该系统工作稳定可靠,具有较高的应用价值。     

过采样CPM信号的频域均衡

提出了一种直接对过采样的连续相位调制(CPM)信号进行单载波频域均衡的算法,同时提出了一种在插入循环前缀后发送CPM信号的相位仍然连续的方法。仿真结果表明,该单载波频域均衡算法能有效地消除大时延信道冲击响应下的CPM接收信号中的码间串扰。与现有的基于匹配滤波、符号抽样的CPM信号的单载波频域均衡算法相比,其性能和复杂度相当,但是CPM接收机的前端更为简单。     

Internetworking VCSEL-Based Hybrid Base Station Towards Simultaneous Wireless and Wired Transport for Converged Access Network

A hybrid base-station (H-BS) scheme that has the potential to establish intercommunications among neighboring access nodes without sending the signals to the edge node to simultaneously transport wireless and wireline services to integrated access nodes is proposed. As the scheme uses vertical-cavity surface-emitting lasers as the light source in the H-BS, it can potentially be realized at low cost without any temperature control.