Universal quality measurement system for multimedia and other signals

• US 6,819,924 B1
• Filed: 01/24/2001
• Issued: 11/16/2004
• Est. Priority Date: 05/25/1999
• Status: Expired due to Term

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Ma, Wei, Lee, Martin, Homayounfar, Kambiz
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Jackson, Blane J.
• Application Number:
  US09/744,521
• Time in Patent Office: 1,392 Days
• Field of Search: 455/67.11, 455/423, 455/424, 455/425, 455/67.13, 455/67.14, 455/63.1, 370/241, 370/249
• US Class Current: 455/425
• CPC Class Codes: H04M 3/2236 Quality of speech transmission monitoring
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

A method for measuring perceptual quality of voice signals, audio signals, audio-video signals, and multimedia signals in communication equipment in an operational embodiment communicates a processed test signal via a network from a first device to a second device. The processed test signal is then received by an equipment under test, which further processes the processed test signal to recover a representation of the test signal. The recovered test signal is then objectively analyzed to determine a measure of perceptual quality by comparing the recovered test signal to a pre-stored representation of the test signal.

A quality measurement unit that conveniently attaches to equipment under test identifies and evaluates quality of recovered test signals communicated from a remote device, or a test signal communicated by the equipment under test. In the latter case, the quality measurement unit communicates with both the equipment under test and with the network, so that the quality measurement unit itself receives a representation of the communicated test signal by the equipment under test.

Claims

1. A method for measuring perceptual quality of at least one of voice signals, audio signals, audio-video signals and multimedia signals in communication equipment in an operational environment comprising the steps of:

transmitting a processed test signal via a communication network from a first device, wherein the test signal is at least one of a voice signal, audio signal, audio-video signal, and multimedia signal;

receiving the processed test signal utilizing a second device operatively coupled to the first device for injecting a signal into first device for transmission as the test signal and to the network for receiving the test signal;

processing the processed test signal to recover a representation of the test signal;

injecting a representation of the test signal in to the first device utilizing the second device;

further processing the representation of the test signal utilizing the first device;

transmitting the processed representation of the test signal to the second device via the network; and

analyzing perceptual quality of the recovered representation of the test signal by comparing the recovered representation of the test signal to a pre-stored representation of the test signal and comparing the recovered test signal to a pre-stored representation of the test signal.

2. A method in accordance with claim 1 wherein the first device comprises a remote data storage unit (RRDSU) operatively coupled to the network to communicate a processed test signal therethrough, and the second device comprises an item of equipment under test (EUT) operatively coupled to the network for receiving the processed test signal and to a quality measurement unit (QMU) for analyzing quality of the recovered test signal;

said method further comprising the step of analyzing signals recovered by the EUT to determine that a test signal has been recovered prior to said step of analyzing quality of the recovered test signal.

3. A method in accordance with claim 2 further comprising the step of the QMU displaying an indication of the quality of the recovered test signal.

4. A method in accordance with claim 2 further comprising the step of contacting the RRDSU from the EUT via the network prior to said step of communicating the processed test signal.

5. A method in accordance with claim 4 wherein the network comprises a telephone network, the EUT comprises a telephone, and said step of contacting the RRDSU from the EUT via the network comprises the step of dialing a phone number of the RRDSU.

6. A method in accordance with claim 5 wherein the step of contacting the RRDSU from the EUT further comprises the step of dialing a voice mailbox access code.

7. A method in accordance with claim 2 wherein said step of analyzing quality of the recovered test signal is performed while the processed test signal is being received by the EUT.

8. A method in accordance with claim 2 further comprising the step of storing the recovered test signal, and wherein said step of analyzing quality of the recovered test signal is performed after the test signal has been stored.

9. A method in accordance with claim 8 wherein said further comprising the step of disconnecting the EUT from the network prior to said step of analyzing quality of the recovered test signal.

10. A method in accordance with claim 2 wherein said step of analyzing quality of the recovered test signal is performed digitally.

11. A method in accordance with claim 2 further comprising a step of selecting a quality assessment method in accordance with a characteristic of the network.

12. A method in accordance with claim 2 wherein the network is a wireless telephone network, said steps of communicating a processed test signal and of analyzing quality of the recovered test signal are performed repeatedly, and said method further comprises the steps of:

moving the EUT so that the repeated communications of the processed test signal are received in different positions of the EUT; and

analyzing quality of the recovered test signals as a function of the different positions of the EUT.

13. A method in accordance with claim 2 wherein processed test signal communicated by the first device to the second device is a processed representation of a first test signal, and further comprising the steps of:

injecting a representation of a second test signal into the EUT utilizing the QMU;

further processing the second test signal utilizing the EUT;

communicating the processed second test signal from the EUT to the first device via the network; and

further processing the communicated, processed second test signal to recover a representation of the second test signal utilizing the first device; and

objectively analyzing perceptual quality of the recovered second test signal by comparing the recovered second test signal to a pre-stored representation of the second test signal.

14. A method in accordance with claim 13 further comprising separately storing results of the analysis of the quality of the recovered first test signal and of the recovered second test signal, and associating time stamps with each of the separately stored results for later correlation and further processing of the separately stored results.

15. A method in accordance with claim 1 wherein the first device comprises equipment under test (EUT) and the second device comprises a quality measurement unit (QMU).

16. A quality measurement device for measuring quality of signals transmitted via a communication network to equipment under test (EUT), said quality measurement device comprising a local reference data storage unit (LRDSU) having a representation of a test signal stored therein, and further configured to control the EUT to communicate a processed representation of said test signal via the network, said quality measurement device configured to:

communicate with the EUT;

analyze signals received and recovered by the EUT to identify recovered test signals;

objectively analyze perceptual quality of said identified and recovered test signal while a processed said test signal is being received by the EUT;

receive, via the network, a representation of said test signal communicated by the EUT under control of said quality measurement device, and

objectively analyze perceptual quality of said test signal communicated via the network to said quality measurement device.

17. A quality measurement device in accordance with claim 16 further configured to analyze at least one type of said test signal selected from the group consisting of voice signals, audio signals, video signals, and multimedia signals.

18. A quality measurement device in accordance with claim 17 further configured to display an indication of the quality of said identified and recovered test signal.

19. A quality measurement device in accordance with claim 17 further configured to synchronize with test signals recovered by the EUT to identify said recovered test signal.

20. A quality measurement device in accordance with claim 17 further comprising local storage, said quality measurement device further configured to store said identified and recovered test signal in said local storage and to analyze said identified and recovered test signal after storage.

21. A quality measurement device in accordance with claim 20 further configured to effect disconnection of the EUT from the network prior to said quality measurement device analyzing said identified and recovered test signal.

22. A quality measurement device in accordance with claim 17 further configured to select a quality assessment method for objectively analyzing perceptual quality of said identified and recovered test signal in accordance with a characteristic of the network.

23. A quality measurement device in accordance with claim 16 further configured to communicate with a wireless telephone as the EUT.

24. A quality measurement device in accordance with claim 16 further configured to record indications of objective perceptual quality of said recovered and identified test signal and to timestamp said recorded indications of quality.