04-16-2009, 11:33 PM
Let's look at the data rates of various technologies.
- A standard voice circuit for telephone has an audio bandwidth of 4 Khz, and a data rate of 64 Kb/s.
- An FM radio station has an audio bandwidth of 15 Khz.
- HD radio has a data rate of as little as 100 kb/s
Understand that when telephone channels were engineered to have an audio bandwidth of 4 Khz, the goal was to make someone understandable, NOT to provide high fidelity. In a time division multiplexer, each channel is sample at a rate of 4 Khz, and each sample is 8 bits, which is how you get 64 Kb/s. An FM radio channel that has a 15 Khz wide baseband would have to be sample at 30 Khz. If each sample was 8 bits, you'd have a data rate of 240 Kb/s. For one channel...
As a comparison, the audio on a compact disc is 720 Kb/s, and each sample is 16 bits
- A standard voice circuit for telephone has an audio bandwidth of 4 Khz, and a data rate of 64 Kb/s.
- An FM radio station has an audio bandwidth of 15 Khz.
- HD radio has a data rate of as little as 100 kb/s
Understand that when telephone channels were engineered to have an audio bandwidth of 4 Khz, the goal was to make someone understandable, NOT to provide high fidelity. In a time division multiplexer, each channel is sample at a rate of 4 Khz, and each sample is 8 bits, which is how you get 64 Kb/s. An FM radio channel that has a 15 Khz wide baseband would have to be sample at 30 Khz. If each sample was 8 bits, you'd have a data rate of 240 Kb/s. For one channel...
As a comparison, the audio on a compact disc is 720 Kb/s, and each sample is 16 bits