基于低压配电网传输的公共广播系统（PAS）
|
摘要
公共广播系统(Public Address System，简称PAS)是智能大厦、机场、车站、综合大楼等公共场所所必备的设备，其应用范围极为广泛。但是目前的PAS存在着布线量较大、系统维护不便和分区方式不灵活等缺点。本文要解决的问题是如何利用低压电力线作为PAS的传输介质，研制基于低压配电网传输的PAS，克服传统PAS在应用中存在的缺点。
文章首先对目前PAS的应用现状进行了简单介绍，提出基于低压配电网传输的PAS的研究设想，新的PAS具有免布线、维护方便、分区灵活和易于扩展等优点。同时，指出课题研究的难点主要在于电力线作为通信介质存在技术上的难度。
在对低压电力线路的噪声特性、衰减特性和阻抗特性三个方面充分分析的基础上，本文提出一种语音编码+扩频传输的系统总体方案，采用扩频载波(Spread Spectrum Carrier，缩写为SSC)技术克服电力线传输信号存在的问题，采用语音合成质量高并具有较低码率的MBE压缩算法完成语音信号的编解码。课题选用相关的产品完成了系统的硬件设计和软件设计。
本文对研制成功的实验系统进行了数据传输能力和语音传输质量的测试。通过对实验结果的分析可知影响数据传输能力主要有两个因素：发送信号的幅度和信号的载波频率。系统合成语音的质量较好，具有较高的清晰度和自然度。实验结果表明本设计方案合理，传输可靠，语音质量高，可以用于公共场所的语音广播，克服传统PAS的缺点。系统还需要在两个方面进行改进：(1)抵抗低压电力线恶劣通信状况的能力；(2)适合于音乐信号的传送。
系统的研制成功使得将来有可能在如下课题开展研究：基于低压配电网传输的音／视频系统，如内部电话系统或可视对讲系统。
Public Address System(abbreviated as PAS) is a necessary equipment for public places such as intelligent building, airport, railway station and integrated building and has a wide range of applications. However, current PAS has the disadvantages such as requiring a large amount of wiring, inconvenient system maintenance and inflexible area-dividing mode. The objective of this paper is to utilize low-voltage power line as the transmission medium of PAS and develop a PAS based on transmission over low-voltage power distribution networks, in order to resolve the defects existing in conventional PAS.
The paper made a brief introduction to present application status of PAS and brought up the idea of researching on PAS based on transmission over low-voltage power distribution networks. New PAS possesses advantages such as avoiding wiring, convenient maintenance, flexible area-dividing mode and readily expanding. Hindrance to Research is that the using of power line as a communication medium has technical difficulties.
System scheme of Speech coding plus Spread Spectrum Communication was presented based on a full analysis of noise characteristic, attenuation characteristic and impedance characteristic of low-voltage power line. Spread Spectrum Carrier(abbreviated as SSC) technology is adopted to overcome problems existing in signal transmission over power line. High quality, low rate MBE compression algorithm was used to complete speech encoding and decoding. Relative products were selected to carry out system's hardware and software design. The successfully developed experimental system was tested to evaluate the data transmission ability and speech quality of the system. Analysis of testing results showes that two factors mainly influence data transmission ability: transmitting signal's amplitude and carrier frequency. Good speech quality is found to have high clarity and naturalness. Experimental results have demonstrated that the scheme is reasonable and can be used for public places addressing. The system requires two improvements: (1) the ability to counter the severe communication condition of low-voltage power line and (2) the ability to transmit music signal.
The success of system study has made it possible to launch researches on
VI
following topic: audio/video system based on the transmission over low-voltage power distribution networks, for example, internal telephone system or picture intercom system.
文章首先对目前PAS的应用现状进行了简单介绍，提出基于低压配电网传输的PAS的研究设想，新的PAS具有免布线、维护方便、分区灵活和易于扩展等优点。同时，指出课题研究的难点主要在于电力线作为通信介质存在技术上的难度。
在对低压电力线路的噪声特性、衰减特性和阻抗特性三个方面充分分析的基础上，本文提出一种语音编码+扩频传输的系统总体方案，采用扩频载波(Spread Spectrum Carrier，缩写为SSC)技术克服电力线传输信号存在的问题，采用语音合成质量高并具有较低码率的MBE压缩算法完成语音信号的编解码。课题选用相关的产品完成了系统的硬件设计和软件设计。
本文对研制成功的实验系统进行了数据传输能力和语音传输质量的测试。通过对实验结果的分析可知影响数据传输能力主要有两个因素：发送信号的幅度和信号的载波频率。系统合成语音的质量较好，具有较高的清晰度和自然度。实验结果表明本设计方案合理，传输可靠，语音质量高，可以用于公共场所的语音广播，克服传统PAS的缺点。系统还需要在两个方面进行改进：(1)抵抗低压电力线恶劣通信状况的能力；(2)适合于音乐信号的传送。
系统的研制成功使得将来有可能在如下课题开展研究：基于低压配电网传输的音／视频系统，如内部电话系统或可视对讲系统。
Public Address System(abbreviated as PAS) is a necessary equipment for public places such as intelligent building, airport, railway station and integrated building and has a wide range of applications. However, current PAS has the disadvantages such as requiring a large amount of wiring, inconvenient system maintenance and inflexible area-dividing mode. The objective of this paper is to utilize low-voltage power line as the transmission medium of PAS and develop a PAS based on transmission over low-voltage power distribution networks, in order to resolve the defects existing in conventional PAS.
The paper made a brief introduction to present application status of PAS and brought up the idea of researching on PAS based on transmission over low-voltage power distribution networks. New PAS possesses advantages such as avoiding wiring, convenient maintenance, flexible area-dividing mode and readily expanding. Hindrance to Research is that the using of power line as a communication medium has technical difficulties.
System scheme of Speech coding plus Spread Spectrum Communication was presented based on a full analysis of noise characteristic, attenuation characteristic and impedance characteristic of low-voltage power line. Spread Spectrum Carrier(abbreviated as SSC) technology is adopted to overcome problems existing in signal transmission over power line. High quality, low rate MBE compression algorithm was used to complete speech encoding and decoding. Relative products were selected to carry out system's hardware and software design. The successfully developed experimental system was tested to evaluate the data transmission ability and speech quality of the system. Analysis of testing results showes that two factors mainly influence data transmission ability: transmitting signal's amplitude and carrier frequency. Good speech quality is found to have high clarity and naturalness. Experimental results have demonstrated that the scheme is reasonable and can be used for public places addressing. The system requires two improvements: (1) the ability to counter the severe communication condition of low-voltage power line and (2) the ability to transmit music signal.
The success of system study has made it possible to launch researches on
VI
following topic: audio/video system based on the transmission over low-voltage power distribution networks, for example, internal telephone system or picture intercom system.
引文
[1]郭宏伟．公共广播系统设计及设备选型．http://www.tvtech.com.cn/,2002
[2]DSPPA公共广播工程手册．广州声雅音响器材公司工程部编译，2001
[3]链码自适应电力线数字通讯技术介绍书．深圳维方电子技术开发有限公司，2001
[4]张士文，殳国华，韩正之．低压电力线通信技术综述．华北电力技术，2002(1)
[5]刘海涛，陈长德，张保会．低压电力线通信传输环境研究．电力自动化设备，2001(9)
[6] Morgan H,Chan L,Robert W.Attenuation of communication signals on residential and commercial intrabuilding power distribution circuits[J].IEEE Trans.on Electromagnetic Compatibility,1986,28(4): 220-230.
[7] Van Der Gracht P K,Donaldson R W.Communication Using Pseudonoise Modulation on Electric Power Distribution Circuits[J].IEEE Trans on Communications,1985,COM33(9):964-974.
[8] 李建坤，徐政勋．低压电力线载波通讯信道的分析与载波信号注入耦合电路的设计．电测与仪表，2002(6)
[9] Nicholson J R,Malak J A.RF Impedance of Power Lines and Line Impedance Stabilization in Conducted Interference Measurements[J].IEEE Trans on Electromagnetic Compatibility,1973,EMC-15:84-86
[10] Malak J A,Engstorm J R.RF Impedance of United States and European Power Lines[J].IEEE Trans on Electromagnetic Compatibility,1976,EMC-18(1):36-38
[11] Vines R M,Tmssel M J,Shuey K C,et al.Impedance of Residential Power-Distribution Circuit[J].IEEE Trans on Electromagnetic Compatibility,1985,EMC-27(1):6-12.
[12] Hooijen O G.A Channel Model for the Residential Power Circuit used as a Digital Communications Medium[J].IEEE Trans on Electromagnetic Compatibility,1998,EMC-40(4):333-336
[13] 陈健．DSP技术及其应用讲座—第五讲语音信号压缩编码．电子技术，1998
(2)
[14]付强，张德民。多带激励语音压缩算法的仿真实现．重庆邮电学院学报，1996(4)
[15]SSC P300 PL Network Interface Controller Technical Data Sheet.Intellon,1998
[16]李永刚，田远富，羿飒．SSCP300芯片在低压电网抄表系统中的应用．电子技术，2001(5)
[17]EIA-600.31-PL Physical Layer & Medium Specification.Electronic Industries Association,1995
[18]杨春萍，崔维新，孙凤杰．语音压缩编码技术在数字式电力线载波机中的应用．现代电力，2002(2)
[19]刘斌，张欣．高效语音压缩芯片AMBE-200~(TM)及其在语音压缩中的应用．现代电子技术，2002(3)
[20]AMBE-2020~(TM) Vocoder Chip User's Manual(Vemion 3.0).Distal Voice Systems,Inc.,2000
[21]张歆亦，卢敦陆，张有为．AD73311通用模拟前端的原理及其在语音处理中的应用．电子技术应用，1999(8)
[22]AMBE-2000~(TM) and AMBE-2020~(TM) Vocoder Chip Interface Applications Note:Interfacing DVSI's AMBE-2000~(TM) and AMBE-2020~(TM) Vocoder Chips with the Analog Devices AD73311 Codec.2002
[23]Mike Magdaluyo.3V与5V混合系统中逻辑器接口问题．21IC中国电子网BBS精华版．2002
[24]蒋翔。单片机程序设计中运用事件：驱动机制．电子技术应用，2002(7)
[25]姚剑清．语音与音乐压缩技术的比较．电子产品世界，2001(12A)
[26]DL／T698-1999标准：电力行业标准低电压用户集中抄表系统技术条件(试行)
[27]4.8kbps多带激励语音编码器的模拟实现．西安电子科技大学学报，1995(3)
[28]王炳锡．语音编码．西安：西安电子科技大学出版社，2002
[29]马忠梅．单片机的C语言应用程序设计．北京：北京航空航天大学出版社，1999
[30]孙育才．MCS-51系列单片微型计算机及其应用．南京：东南大学出版社，1997
[31]邱关源．电路(上、下册)．北京：高等教育出版社，1989
[32]张振昭，许锦标，万频．楼宇智能化技术．北京：机械工业出版社，1999
[33]王秉均，窦晋江，张广森等．通信原理及其应用．天津：天津大学出版社，2000
[34]刘红．电力线载波收发器的设计及优化：[硕士学位论文]．哈尔滨：哈尔滨工业大学图书馆，2001
[35]韦团．基于电力线扩频载波的CEBus在家庭智能化中的应用：[硕士学位论文]．北京：北京工业大学图书馆，2001
[36]AD73311 General Purpose Analog Front End Technical Data Sheet.Analog Devices,Inc.,2000
[37]Application Note #0069: Using Intellon's Serial Peripheral Interface.Intellon,1999
[38]Application Note #0064: Your First CEBUS Packet.Intellon,1997
[39]SSC P200 and P300 Hardware Design Reference.Intellon,1998
[40]BS EN500065:2001: Signalling on Low-voltage Electrical Installations in the frequency range 3kHz to 148.5kHz-Part1:General Requirements,Frequency Bands and Electromagnetic Disturbances.The European Committee for Electrotechnical Standardization,2001
[41]张有兵，何海波，吴昕等．低压电力线载波通信中信道模型的研究．继电器，2002(5)
[42]李伟波，李伟，王宇等．一种电力线扩频载波通讯节点的具体实现．电子技术应用，2002(1)
[43]史贤俊，聂子玲．基于SSCP300的电力线扩频载波通讯电路的设计．国外电子元器件，2002(1)
[2]DSPPA公共广播工程手册．广州声雅音响器材公司工程部编译，2001
[3]链码自适应电力线数字通讯技术介绍书．深圳维方电子技术开发有限公司，2001
[4]张士文，殳国华，韩正之．低压电力线通信技术综述．华北电力技术，2002(1)
[5]刘海涛，陈长德，张保会．低压电力线通信传输环境研究．电力自动化设备，2001(9)
[6] Morgan H,Chan L,Robert W.Attenuation of communication signals on residential and commercial intrabuilding power distribution circuits[J].IEEE Trans.on Electromagnetic Compatibility,1986,28(4): 220-230.
[7] Van Der Gracht P K,Donaldson R W.Communication Using Pseudonoise Modulation on Electric Power Distribution Circuits[J].IEEE Trans on Communications,1985,COM33(9):964-974.
[8] 李建坤，徐政勋．低压电力线载波通讯信道的分析与载波信号注入耦合电路的设计．电测与仪表，2002(6)
[9] Nicholson J R,Malak J A.RF Impedance of Power Lines and Line Impedance Stabilization in Conducted Interference Measurements[J].IEEE Trans on Electromagnetic Compatibility,1973,EMC-15:84-86
[10] Malak J A,Engstorm J R.RF Impedance of United States and European Power Lines[J].IEEE Trans on Electromagnetic Compatibility,1976,EMC-18(1):36-38
[11] Vines R M,Tmssel M J,Shuey K C,et al.Impedance of Residential Power-Distribution Circuit[J].IEEE Trans on Electromagnetic Compatibility,1985,EMC-27(1):6-12.
[12] Hooijen O G.A Channel Model for the Residential Power Circuit used as a Digital Communications Medium[J].IEEE Trans on Electromagnetic Compatibility,1998,EMC-40(4):333-336
[13] 陈健．DSP技术及其应用讲座—第五讲语音信号压缩编码．电子技术，1998
(2)
[14]付强，张德民。多带激励语音压缩算法的仿真实现．重庆邮电学院学报，1996(4)
[15]SSC P300 PL Network Interface Controller Technical Data Sheet.Intellon,1998
[16]李永刚，田远富，羿飒．SSCP300芯片在低压电网抄表系统中的应用．电子技术，2001(5)
[17]EIA-600.31-PL Physical Layer & Medium Specification.Electronic Industries Association,1995
[18]杨春萍，崔维新，孙凤杰．语音压缩编码技术在数字式电力线载波机中的应用．现代电力，2002(2)
[19]刘斌，张欣．高效语音压缩芯片AMBE-200~(TM)及其在语音压缩中的应用．现代电子技术，2002(3)
[20]AMBE-2020~(TM) Vocoder Chip User's Manual(Vemion 3.0).Distal Voice Systems,Inc.,2000
[21]张歆亦，卢敦陆，张有为．AD73311通用模拟前端的原理及其在语音处理中的应用．电子技术应用，1999(8)
[22]AMBE-2000~(TM) and AMBE-2020~(TM) Vocoder Chip Interface Applications Note:Interfacing DVSI's AMBE-2000~(TM) and AMBE-2020~(TM) Vocoder Chips with the Analog Devices AD73311 Codec.2002
[23]Mike Magdaluyo.3V与5V混合系统中逻辑器接口问题．21IC中国电子网BBS精华版．2002
[24]蒋翔。单片机程序设计中运用事件：驱动机制．电子技术应用，2002(7)
[25]姚剑清．语音与音乐压缩技术的比较．电子产品世界，2001(12A)
[26]DL／T698-1999标准：电力行业标准低电压用户集中抄表系统技术条件(试行)
[27]4.8kbps多带激励语音编码器的模拟实现．西安电子科技大学学报，1995(3)
[28]王炳锡．语音编码．西安：西安电子科技大学出版社，2002
[29]马忠梅．单片机的C语言应用程序设计．北京：北京航空航天大学出版社，1999
[30]孙育才．MCS-51系列单片微型计算机及其应用．南京：东南大学出版社，1997
[31]邱关源．电路(上、下册)．北京：高等教育出版社，1989
[32]张振昭，许锦标，万频．楼宇智能化技术．北京：机械工业出版社，1999
[33]王秉均，窦晋江，张广森等．通信原理及其应用．天津：天津大学出版社，2000
[34]刘红．电力线载波收发器的设计及优化：[硕士学位论文]．哈尔滨：哈尔滨工业大学图书馆，2001
[35]韦团．基于电力线扩频载波的CEBus在家庭智能化中的应用：[硕士学位论文]．北京：北京工业大学图书馆，2001
[36]AD73311 General Purpose Analog Front End Technical Data Sheet.Analog Devices,Inc.,2000
[37]Application Note #0069: Using Intellon's Serial Peripheral Interface.Intellon,1999
[38]Application Note #0064: Your First CEBUS Packet.Intellon,1997
[39]SSC P200 and P300 Hardware Design Reference.Intellon,1998
[40]BS EN500065:2001: Signalling on Low-voltage Electrical Installations in the frequency range 3kHz to 148.5kHz-Part1:General Requirements,Frequency Bands and Electromagnetic Disturbances.The European Committee for Electrotechnical Standardization,2001
[41]张有兵，何海波，吴昕等．低压电力线载波通信中信道模型的研究．继电器，2002(5)
[42]李伟波，李伟，王宇等．一种电力线扩频载波通讯节点的具体实现．电子技术应用，2002(1)
[43]史贤俊，聂子玲．基于SSCP300的电力线扩频载波通讯电路的设计．国外电子元器件，2002(1)