bandwidth - ratio of bits/hz of digitized voice channel -


we need transmit 100 digitized voice channels using passband channel of 30 khz. should ratio of bits/hz if use no guard band?

what understand , bandwidth :

30 khz / 100 = 300 hz

and ratio of bit/hz if no guard band 640000/300 = 213.333... bits/hz (because digitized voice channel has date rate of 64 kbps)

is right answers?

digitization scheme. high quality pcm - 144 kbps, pcm (dso) - 64 kbps, cvsd - 32 kbps, compressed - 16 kbps, lpc - 2.4 kbps.

assuming dso, have 100 channels @ 64 kbps or 6400 kbps send on 20 khz channel. 6400 kbps / 20 khz = 320 b/hz. rather high packing done on noise-free channel.

entropic multiplexing (don't send silent time) reduce factor of 5-10 32-64 k/hz.


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