| ??? 02/01/05 22:44 Read: times |
#86330 - Telephone Quality Responding to: ???'s previous message |
Hans Van Pelt said:
For telephone quality you will need up to 3500 Hz, so about 70000 baud. POTS (Plain Old Telephone Service) analogue bandwidth is 400Hz to 4kHz. Therefore, an 8kHz sample rate is required. Phone systems use 8 bits (one octet) per sample, so that's a total of 64k bits/second (note: that's a lowercase 'k'). On a UART link, you also need a start bit and a stop bit for each octet (8-bit sample) - so 10 bits have to be transferred per sample, giving a total of 80k bits per second. And that's assuming that every single stop bit is immediately followed by the next start bit - with no delay whatsoever between characters... |
| Topic | Author | Date |
| digital audio with 89s52 | 01/01/70 00:00 | |
| coexist | 01/01/70 00:00 | |
| reply to mr erik | 01/01/70 00:00 | |
| make serial processing interrupt driven | 01/01/70 00:00 | |
| thanks but i don't know C | 01/01/70 00:00 | |
| Ring-buffer | 01/01/70 00:00 | |
| re: digital audio with 89s52 | 01/01/70 00:00 | |
| Telephone Quality | 01/01/70 00:00 | |
| thanks every body | 01/01/70 00:00 | |
| Sampled data systems recommended reading | 01/01/70 00:00 | |
Dear Mr Hans Van Pelt | 01/01/70 00:00 |