Modem with voice processing capability

• US RE46,142 E1
• Filed: 09/09/2014
• Issued: 09/06/2016
• Est. Priority Date: 04/13/1999
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Thi, James C., Rabenko, Theodore F., Hartman, David, Lukas, Robert M., Unger, Kenneth J., Borazjani, Ramin, Lansing, Shane P., Lee, Robert J., Brooks, Todd L., Miller, Kevin L.
• Primary Examiner(s): TON, MY TRANG
• Application Number:
  US14/481,349
• Time in Patent Office: 728 Days
• Field of Search: 370/392, 379/406.91, 379/406.1
• US Class Current: 1/1
• CPC Class Codes: H04B 3/23 using a replica of transmitted signal in the time domain, e.g. echo cancellers
• CPC Class Codes: H04B 3/234 using double talk detection
• CPC Class Codes: H04J 3/0632 Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] queuing arrangements in packet switching elements H04L49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N7/56
• CPC Class Codes: H04J 3/0638 Clock or time synchronisation among nodes; Internode synchronisation synchronization for ring networks H04L12/422; data switching networks with synchronous transmission H04L12/43
• CPC Class Codes: H04L 12/28 characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] wireless communication networks H04W ; arrangements for dividing the transmission path H04W40/00
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2834 Switching of information between an external network and a home network access arrangements H04L12/2856
• CPC Class Codes: H04L 12/5692 Selection among different networks
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 29/06027 Protocols for multimedia communication
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/0087 Network planning or provisioning
• CPC Class Codes: H04M 7/125 Details of gateway equipment
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 7/10 Adaptations for transmission by electrical cable H04N7/12 takes precedence

Abstract

A system is configured to facilitate bidirectional voice communication between a number of data and/or telephony devices.

Claims

1. A method of processing signals, the method comprising:

transmitting a first data signal from a first device to a second device, wherein the first data signal is associated with a first voice signal;

receiving a second data signal at the first device from the second device, wherein the second data signal is associated with a second voice signal;

filtering, using a digital filter, the second voice signal to thereby generate an estimated echo signal;

detecting whether speech is present in the first voice signal;

when speech is detected to be present in the first voice signal, disabling adaptation of the digital filter;

delaying the first voice signal to thereby output a delayed first voice signal; and

subtracting, using a difference operator, the estimated echo signal from the delayed first voice signal, wherein a delay for the delayed first voice signal is chosen such that the disabling adaptation occurs prior to the delayed first voice signal reaching the difference operator when speech is detected to be present in the first voice signal.

2. The method of claim 1, further comprising:

converting the first voice signal into the first data signal; and

converting the second data signal into the second voice signal.

3. The method of claim 1, wherein:

the first data signal is transmitted over a local area network; and

the second data signal is received from the local area network.

4. The method of claim 1, wherein:

the delaying of the first voice signal includes using a look ahead buffer.

5. The method of claim 1, wherein detecting whether the speech is present in the first voice signal comprises:

estimating an absolute value of the first voice signal;

estimating a maximum parameter of the first voice signal;

comparing the estimated absolute value of the first voice signal to the estimated maximum parameter of the first voice signal; and

detecting the speech on the first voice signal based on the comparison.

6. The method of claim 1, further comprising:

pre-conditioning the first voice signal prior to the detecting whether the speech is present.

7. The method of claim 1, wherein:

detecting whether speech is present occurs after subtracting the estimated echo signal from a late point in the first voice signal; and

filtering the second voice signal occurs based on speech being detected at an early point in the first voice signal, wherein a time period exists between the early point in the first voice signal and the late point in the first voice signal.

8. The method of claim 1, further comprising:

synchronizing the transmitting and the receiving.

9. The method of claim 8, wherein the synchronizing comprises:

generating an error signal based on a function of a difference between a first device clock and a second device clock; and

fractionally resampling the first voice signal based on a function of the error signal.

10. The method of claim 1, further comprising:

determining whether a received signal is associated with a voice call or associated with a machine communication.

11. The method of claim 1, wherein the first device and the second device are connected to a packet based network.

12. The method of claim 11, wherein the packet based network communicates data modulated at a frequency above a frequency of a voiceband signal.

13. The method of claim 1, further comprising:

modulating the first data signal flowing over a local area network from the first device; and

demodulating the second data signal flowing from over the local area network to the first device.

14. The method of claim 1, further comprising:

adapting the digital filter when speech is not detected to be present.

15. The method of claim 1, further comprising:

transmitting a grant receive value to the second device; and

receiving packets in the second data signal from the second device in accordance with the grant receive value, wherein the packets arrive prior to a subsequent grant.

17. The method of claim 1, further comprising:

receiving a grant receive value from the second device; and

transmitting packets in the first data signal to the second device in accordance with the grant receive value, wherein the packets are transmitted prior to a subsequent grant.

16. A method of processing signals, the method comprising:

transmitting a first data signal from a first device to a second device, wherein the first data signal is associated with a first voice signal;

receiving a second data signal at the first device from the second device, wherein the second data signal is associated with a second voice signal;

detecting whether speech is present in the first voice signal;

when speech is detected to be present, subtracting an estimated echo signal from the first voice signal, wherein the estimated echo signal is generated by filtering the second voice signal with a digital filter;

transmitting a grant receive value to the second device;

receiving packets in the second data signal from the second device in accordance with the grant receive value, wherein the packets arrive prior to a subsequent grant; and

generating a packet assembly start time based on an offset value, the grant receive value, a packet assembly overhead, a queuing latency and a transmission time.

18. A method of processing signals, the method comprising:

transmitting a first data signal from a first device to a second device, wherein the first data signal is associated with a first voice signal;

receiving a second data signal at the first device from the second device, wherein the second data signal is associated with a second voice signal;

detecting whether speech is present in the first voice signal;

when speech is detected to be present, subtracting an estimated echo signal from the first voice signal, wherein the estimated echo signal is generated by filtering the second voice signal with a digital filter;

receiving a grant receive value from the second device;

transmitting packets in the first data signal to the second device in accordance with the grant receive value, wherein the packets are transmitted prior to a subsequent grant; and

generating a packet assembly start time based on an offset value, the grant receive value, a packet assembly overhead, a queuing latency and a transmission time.

19. A system for processing signals, the system comprising:

at least one processor for use in a first device, said at least one processor being configured to;

transmit a first data signal destined for a second device, wherein the first data signal is associated with a first voice signal;

receive a second data signal from the second device, wherein the second data signal is associated with a second voice signal;

detect whether speech is present in the first voice signal;

filter the second voice signal with a digital filter, thereby generating an estimated echo signal;

when speech is detected to be present in the first voice signal, disable adaptation of the digital filter;

delay the first voice signal to output a delayed first voice signal; and

subtract, using a difference operator, the estimated echo signal from the delayed first voice signal, wherein a delay for the delayed first voice signal is chosen such that the adaptation disablement occurs prior to the delayed first voice signal reaching the difference operator when speech is detected to be present in the first voice signal.

20. The system of claim 19, wherein the at least one processor is further configured to:

convert the first voice signal into the first data signal; and

convert the second data signal into the second voice signal.

21. The system of claim 19, wherein the at least one processor is further configured to:

transmit the first data signal over a local area network; and

receive the second data signal from the local area network.

22. The system of claim 19, wherein the delay is represented by a predetermined number of samples of the first voice signal.

23. The system of claim 19, wherein the at least one processor is further configured to detect whether the speech is present in the first voice signal by:

estimating an absolute value of the first voice signal;

estimating a maximum parameter of the first voice signal;

comparing the estimated absolute value of the first voice signal to the estimated maximum parameter of the first voice signal; and

detecting the speech on the first voice signal based on the comparison.

24. The system of claim 19, wherein the at least one processor is further configured to pre-condition the first voice signal prior to the detecting whether the speech is present.

25. The system of claim 19, wherein the at least one processor is further configured to:

detect whether speech is present after subtracting the estimated echo signal from a late point in the first voice signal; and

filter the second voice signal based on speech being detected at an early point in the first voice signal, wherein a time period exists between the early point in the first voice signal and the late point in the first voice signal.

26. The system of claim 19, wherein the at least one processor is further configured to synchronize transmitting and receiving.

27. The system of claim 26, wherein the at least one processor is further configured to synchronize by:

generating an error signal based on a function of a difference between a first device clock and a second device clock; and

fractionally resampling the first voice signal based on a function of the error signal.

28. The system of claim 19, wherein the at least one processor is further configured to determine whether a received signal is associated with a voice call or associated with a machine communication.

29. The system of claim 19, wherein the first device and the second device are connected to a packet based network.

30. The system of claim 29, wherein the packet based network communicates data modulated at a frequency above a frequency of a voiceband signal.

31. The system of claim 19, wherein the at least one processor is further configured to:

modulate the first data signal flowing over a local area network from the first device; and

demodulate the second data signal flowing from over the local area network to the first device.

32. The system of claim 19, wherein the at least one processor is further configured to adapt the digital filter when speech is not detected to be present.

33. The system of claim 19, wherein the at least one processor is further configured to:

transmit a grant receive value to the second device; and

receive packets in the second data signal from the second device in accordance with the grant receive value, wherein the packets arrive prior to a subsequent grant.

35. The system of claim 19, wherein the at least one processor is further configured to:

receive a grant receive value from the second device; and

transmit packets in the first data signal to the second device in accordance with the grant receive value, wherein the packets are transmitted prior to a subsequent grant.

34. A system for processing signals, the system comprising:

at least one processor for use in a first device, said at least one processor configured to;

transmit a first data signal destined for a second device, wherein the first data signal is associated with a first voice signal;

receive a second data signal from the second device, wherein the second data signal is associated with a second voice signal;

detect whether speech is present in the first voice signal;

filter the second voice signal with a digital filter, thereby generating an estimated echo signal;

subtract the estimated echo signal from the first voice signal;

transmit a grant receive value to the second device;

receive packets in the second data signal from the second device in accordance with the grant receive value, wherein the packets arrive prior to a subsequent grant; and

generate a packet assembly start time based on an offset value, the grant receive value, a packet assembly overhead, a queuing latency and a transmission time.

36. A system for processing signals, the system comprising:

at least one processor for use in a first device, said at least one processor configured to;

transmit a first data signal destined for a second device, wherein the first data signal is associated with a first voice signal;

receive a second data signal from the second device, wherein the second data signal is associated with a second voice signal;

detect whether speech is present in the first voice signal;

filter the second voice signal with a digital filter, thereby generating an estimated echo signal;

subtract the estimated echo signal from the first voice signal;

receive a grant receive value from the second device;

transmit packets in the first data signal to the second device in accordance with the grant receive value, wherein the packets are transmitted prior to a subsequent grant; and

generate a packet assembly start time based on an offset value, the grant receive value, a packet assembly overhead, a queuing latency and a transmission time.