四川邮电职业技术学院教案专用纸 assume[ssju:m]v假髋定 decoder解器 codec编译码器 interleave[int"li:]t.彌插殲播接 appropriate[s' proup r i t]a.适当的合适的 ik]a唯的猫 reoccur再先生再姓生 ii. Passage-reading Activities The Principle of PCM(1) PcM原理 PCM is dependent on(22_three separate operations, sampling, quantizing, and coding(2 ). Many different schemes for performing 2)these three functions have evolved during recent years, and we shall describe the main ones PCM的构成依赖于三个环节即采样、量化和编码.近年来人们对这 三个环节的实现提出了许多不同的方案我们将对其中一些主要的方案进 行讨论 (2). be dependent on依靠,依赖,取决于 (2). performing是 perform的动名词动名词虽为名词,但仍 保留着动词的某些特征,例如它仍可带有动词宾语本句中的 these three functions就是 performing的宾语 本课中这类例子很多,例如第四段中的最后一句中 Consequently there is an inherent advantage for overcoming noisy environments by choosing digital transmission. 句中的 overcomIng和 choosing都是动名词且带有自己的动词宾语. 另有理论认为PCM分为四过程,如下: The practical implementation of PCM makes use of other processes. The processes are carried out in the order in which they appear below Fil tering Quantizing The filtering stage removes frequencies above the highest signal frequency. These frequencies if not removed, may cause problems when the signal is going through the stage of sampling. Sampling of a waveform means determining instantaneous ampli tudes of a signal at fixed intervals. You may have a problem in understanding what this sentence means, but if you take time to look at Figure 7 on the following Slide you should be able to understand. Page 5 of 12 Teaching Plan of English for Telecommunications Unit One四川邮电职业技术学院教案专用纸 Page 5 of 12 Teaching Plan of English for Telecommunications Unit One assume ［ə'ｓｊｕ:ｍ］v. 假设，假定 decoder 解(译)码器 codec 编译码器 interleave ［ｉｎｔ'ｌｉ:ｖ］vt. 交插，交错，插接 appropriate ［ə'ｐｒｏｕｐｒｉｔ］a. 适当的，合适的 unique ［ｊｕ:'ｎｉｋ］a. 唯一的，独特的 reoccur 再发生，再次发生 ii. Passage-reading Activities The Principle of PCM(1) PCM 原理 PCM is dependent on (2 ) three separate operations, sampling, quantizing, and coding (2’). Many different schemes for performing (2) these three functions have evolved during recent years, and we shall describe the main ones. PCM 的构成依赖于三个环节,即采样、量化和编码. 近年来,人们对这 三个环节的实现提出了许多不同的方案,我们将对其中一些主要的方案进 行讨论. ◼ （2）. be dependent on 依靠，依赖，取决于. ◼ （2’）. performing 是 perform 的动名词.动名词虽为名词，但 仍 保留着动词的某些特征，例如它仍可带有动词宾语.本句中的 these three functions 就是 performing 的宾语. 本课中这类例子很多，例如第四段中的最后一句中： Consequently there is an inherent advantage for overcoming noisy environments by choosing digital transmission. 句中的 overcoming 和 choosing 都是动名词且带有自己的动词宾语. ◼ 另有理论认为ＰＣＭ分为四过程，如下： ◼ The practical implementation of PCM makes use of other processes. The processes are carried out in the order in which they appear below: Filtering Sampling Quantizing Encoding The filtering stage removes frequencies above the highest signal frequency. These frequencies if not removed, may cause problems when the signal is going through the stage of sampling. Sampling of a waveform means determining instantaneous amplitudes of a signal at fixed intervals. You may have a problem in understanding what this sentence means, but if you take time to look at Figure 7 on the following Slide, you should be able to understand