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An experiment of 16 channels sequency division mult plex (SDM) system has bsen completed by the RF earner channel for the transmission of telemetry signals. Through th3 bandlimited carrier channel the Walsh subcarrier becomes the pulse waves with front and lagging edges, that will causes the orthogonal error between subcarriers. By using a switch in proper time, the front and lagging edges of pulse can be cut off, so that the seperated Walsh subcarriers are obtained, they are the orthogonal functions too.... An experiment of 16 channels sequency division mult plex (SDM) system has bsen completed by the RF earner channel for the transmission of telemetry signals. Through th3 bandlimited carrier channel the Walsh subcarrier becomes the pulse waves with front and lagging edges, that will causes the orthogonal error between subcarriers. By using a switch in proper time, the front and lagging edges of pulse can be cut off, so that the seperated Walsh subcarriers are obtained, they are the orthogonal functions too. By means of this processing the orthogonal error of the 16 channels system in a carrier channel possessing bandwidth 320KHz can be neglected. On the other hand, the main source of error is caused by the nonlinearity of the RF carrier channel, as a result, the greatest crosstalk is less than 5%,generally speaking, it is satisfactory to eng'neering. Thus, the SDM, as a multiplex system parallel to FDM and TDM, can be perfectly applied to telemetry. 本文介绍一个在一般遥测用射频信道上实现16路沃尔什复用(序率分割复用)系统(SDM)的实验。沃尔什函数作为付载波经带限信道后其波形要产生上升、下降沿,这将导致各路间的正交误差。为此引进间断开关将脉冲上升下降沿部分切除,得到间断沃尔什付载波,它仍是一组正交函数。这样在视频带宽320KHz的通道上传输16路沃尔什多路信号时其正交误差可忽略不计。而误差的主要来源是射频通道非线性引起的交叉干扰,但在目前射频通道的一般水平上交叉干扰最大值小于5%,这已满足一般的工程要求。因此SDM作为一个与FDM和TDM相平行的多路复用系统是完全能用于遥测中的。 According to the theory of orthogonal multiplex, frequency division multiplex (FDM) and time division multiplex (TDM) belong to orthogonal multiplex. FDM and TDM are not the only two multiplex methods which satisfy the orthogonal condition. Walsh functions are orthogonal and complete. As a telemetry system based on Walsh functions, sequency division multiplex (SDM) is theoretically proposed, and its feasibility is verified experimentally. The design concept, block diagram, operational principle and technical... According to the theory of orthogonal multiplex, frequency division multiplex (FDM) and time division multiplex (TDM) belong to orthogonal multiplex. FDM and TDM are not the only two multiplex methods which satisfy the orthogonal condition. Walsh functions are orthogonal and complete. As a telemetry system based on Walsh functions, sequency division multiplex (SDM) is theoretically proposed, and its feasibility is verified experimentally. The design concept, block diagram, operational principle and technical realization are discussed in detail. The laboratory prototype is a WAM-FM system. In order to show the advantage and potentiality, it is compared with FDM. As a. result, the new system is not only of academic value, but also of practical importance.A SDM system using Walsh sub-carriers was developed for transmission of telemetry signals. Crosstalk caused by synchronization errors and by distortions of the subcarriers is investigated. Consequently, rules for selection of the subcarriers are derived to minimize errors caused by poor synchronization. Errors due to distortions of the subcarriers are only of secondary importance in comparison with the errors caused by poor synchronization. 根据正交分割理论,现在流行的频率分割制(FDM)和时间分割制(TDM)都属于正交分割的范畴。满足正交条件的信号不仅仅只有频分和时分两种形式。1923年美国数学家沃尔什(WALSH)提出的沃尔什函数就是一种正交完备的函数系。本文在理论上提出了一种以沃尔什函数为基础的序率分割制(SDM),并以实验证明了新方案是可行的。文中详细地介绍了这种SDM系统的设计思想、方框图、工作原理以及具体实施中的技术问题。实验室研制成的样机是沃尔什调幅——调频制的,称为WAM-FM遥测系统。为了阐明新系统的优越性及其潜力,把它与现行的频分遥测系统作了简单的比较。说明新系统不仅具有一定的学术价值,而且具有一定的实用价值。 A portable up-based demodulator system for the implantable ICP telemeter is described.A HP-85 desk top microcomputer is utilized as the“master”,with the 8749 single chip μc functioning as the I/O processor.The HP-85's CRT also serves as a digital oscilloscope for displaying the waveform of ICP telemetry signal.The interface module incorporates a PLL frequency generator to transmit the RF command signal for ON/OFF control of the ICP telemeter. The μc software carries out temperature compensation,and... A portable up-based demodulator system for the implantable ICP telemeter is described.A HP-85 desk top microcomputer is utilized as the“master”,with the 8749 single chip μc functioning as the I/O processor.The HP-85's CRT also serves as a digital oscilloscope for displaying the waveform of ICP telemetry signal.The interface module incorporates a PLL frequency generator to transmit the RF command signal for ON/OFF control of the ICP telemeter. The μc software carries out temperature compensation,and provides the displaying,recording and monitoring of the ICP signals. 本文叙述了一种便携式颅内压遥测信号微机解调系统。采用 HP-85微计算机作为主机,Intel 8749单片微机作为 I/O 处理器。HP-85的 CRT 兼作数字示波器用来显示 ICP 波形。接口装置还包括一个 PLL 频率发生器用来向 ICP 遥测器发送无线电指令信号。微机系统的软件用来实现温度补偿以及显示、记录、监控等功能。
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