Dual-rate single band communication system
View Patent ↗A system, method, and apparatus for a multiple data rate communication system is presented herein. The communication system receives data samples that are either sampled at a narrowband rate or a wideband rate and provides various functions and services, such as echo cancellation, DTMF detection and generation, and call discrimination. For wideband signals, a down-sampled signal is provided for each of the foregoing function and service. The output of the function or services is then recombined with the wideband signal.
1. A method executed in at least one processor in a terminal for providing signal processing functions to a signal, said method comprising:
receiving digital samples of the signal, wherein the digital samples are sampled at a first sampling rate that is higher than a second sampling rate;
downsampling the received digital samples to produce a narrowband signal at the second sampling rate;
processing the narrowband signal by providing the downsampled digital samples to a dual-tone multi-frequency signaling (DTMF) detector and providing the downsampled digital samples to a call discriminator; and
combining the processed digital samples with the received digital samples.
2. The method of claim 1 , wherein the signal further comprises a wideband signal.
3. The method of claim 2 , wherein the wideband signal is received from a wideband physical device driver.
4. The method of claim 1 , further comprising the step of providing the combined processed digital samples and the received digital samples to a packet voice engine.
5. The method of claim 4 , wherein the packet voice engine is configured to encode and packetize the combined processed digital samples and the received digital samples.
6. The method of claim 1 , further comprising the step of providing the combined processed digital samples and the received digital samples to a switchboard.
7. The method of claim 6 , further comprising the steps of:
performing echo cancellation on an output of the switchboard; and
providing the echo cancelled output to an interpolator.
8. A system for providing signal processing functions to a wideband signal, comprising:
a first downsampler configured to receive digital samples of the wideband signal, wherein the digital samples are sampled at a first sampling rate that is higher than a second sampling rate, the first downsampler configured to downsample the received digital samples to produce a narrowband signal at the second sampling rate;
a DTMF detector configured to detect DTMF tones in the narrowband signal;
a call discriminator configured to process the narrowband signal; and
a combiner configured to combine the processed narrowband signal with the wideband signal.
9. The system of claim 8 , further comprising:
a second combiner configured to combine an output of the DTMF detector with the wideband signal; and
a second downsampler configured to downsample an output of the second combiner to the second sampling rate to produce a second narrowband signal, the second downsampler further configured to provide the second narrowband signal to the call discriminator.
10. The system of claim 8 , wherein the wideband signal is received from a wideband physical device driver.
11. The system of claim 8 , wherein the combiner is configured to provide the combined processed narrowband signal and the wideband signal to a packet voice engine.
12. The system of claim 11 , wherein the packet voice engine is configured to encode and packetize the combined processed digital samples and the received digital samples.
13. The system of claim 8 , wherein the combiner is configured to provide the combined processed narrowband signal and the wideband signal to a switchboard.
14. The system of claim 13 , further comprising:
an echo canceller configured to perform echo cancellation on an output of the switchboard; and
an interpolator configured to receive the echo cancelled output.
15. A system for providing signal processing functions to a wideband signal, comprising:
means for receiving digital samples of the wideband signal, wherein the digital samples are sampled at a first sampling rate that is higher than a second sampling rate means for downsampling the received digital samples to produce a narrowband signal at the second sampling rate;
means for detecting DTMF tones in the narrowband signal;
means for processing the narrowband signal; and
means for combining the processed narrowband signal with the wideband signal.
16. The system of claim 15 , wherein the wideband signal is received from a wideband physical device driver.
17. The system of claim 15 , wherein the combiner is configured to provide the combined processed narrowband signal and the wideband signal to a packet voice engine.
18. The system of claim 17 , wherein the packet voice engine is configured to encode and packetize the combined processed digital samples and the received digital samples.
19. The system of claim 15 , wherein the combining means is configured to provide the combined processed narrowband signal and the wideband signal to a switchboard.
20. The system of claim 19 , further comprising:
means for performing echo cancellation on an output of the switchboard; and
means for interpolating the echo cancelled output.