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据《Telecommunication Journal》1985年7月第7期报道:美国CoherentCommunications Systems公司宣告,它的DSM-32型数字式语言和数据多路器可与56kb/s或64kb/s的宽带数字电路连用。该DSM-32能同时传送32-kb/s的一路数字话音和多达三路的高速数据以及三路像速数据。 DSM-32型产品采用该公司的APCM(自适应脉码调制)数字化技术来把一个模拟话音信号转变成一个32kb/s的数字信号。DSM32型话音通道也可传送速度高达9500b/s的模似调制解调器(V.29信号,但不能与其它话音数字化技术,即GVSD(连续可变斜率△)和ADPCM(自适应差分脉码调制)相兼容。当把相干算法用于类似CVSD调制技术的串联线路时,其结果还改善了话音及数据特性。APCM技术的另一个优点是它具有良好的信噪比,可与64kb/s PCM(脉码调制)和宽带摸拟多路传送设备媲美。
According to Telecommunication Journal, July, 7, 1985, Coherent Communications Systems of the United States announced that its DSM-32 digital language and data multiplexer can be used with 56kb / s or 64kb / s wideband digital circuits. The DSM-32 can simultaneously transmit 32-kb / s digital voice and up to three high-speed data and three-way speed data. The DSM-32 uses the company’s APCM (Adaptive Pulse Code Modulation) digitization technology to convert an analog voice signal into a 32 kb / s digital signal. The DSM32 voice channel also delivers analog modems (V.29 signals) up to 9,500 bps, but not with other voice digitization technologies, GVSD (Continuously Variable Slope Δ) and ADPCM (Adaptive Differential Pulse Code Modulation) The results also improve speech and data characteristics when using coherent algorithms for serial lines like CVSD modulation Another advantage of APCM technology is its good signal to noise ratio that can be used with 64kbps PCMs Code modulation) and broadband analog multiplexer comparable.