System and method for the transmission of an audio or speech signal

• US 7,453,951 B2
• Filed: 06/18/2002
• Issued: 11/18/2008
• Est. Priority Date: 06/19/2001
• Status: Expired due to Fees

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Demeure, Cédric, Laurent, Pierre André
• Primary Examiner(s): Corrielus; Jean B
• Application Number:
  US10/173,243
• Publication Number:
  US 20030012293A1
• Time in Patent Office: 2,345 Days
• Field of Search: 375/295, 375/260, 375/285, 375/222, 375/327, 375/332, 375/341, 375/322, 375/347, 329/304, 370/19, 370/207
• US Class Current: 375/295
• CPC Class Codes: H04H 20/30 by a single channel
• CPC Class Codes: H04H 60/07 characterised by processes or methods for the generation
• CPC Class Codes: H04L 27/00 Modulated-carrier systems
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems

Abstract

A system and method for transmitting an analog signal. The analog signal is converted into complex numbers such that two successive audio samples respectively form a real part and an imaginary part of a respective complex number. The complex numbers are then dispersed in a time-frequency space. The complex numbers are then modulated through a digital modulator into temporal signals and the temporal signals are output for transmission. Thereby, a digital modulator conventionally used for modulating digital input signals can operate for the transmission of an analog signal.

Claims

1. A method for transmitting an analog signal comprising:

inputting said analog signal;

sampling said analog signal at a predetermined frequency to generate a sampled analog signal;

converting the sampled analog signal into complex numbers such that two successive samples of said sampled analog signal respectively form a real part and imaginary part of a respective complex number;

dispersing the complex numbers in a time-frequency space; and

modulating the dispersed complex numbers through a digital modulator into temporal signals and outputting the temporal signals for transmission.

2. A method according to claim 1, further comprising:

pre-processing the sampled analog signal prior to the converting.

3. A method according to claim 2, wherein the pre-processing comprises at least one of pre-accentuation, linear distribution, or dynamic compression of the sampled analog signal.

4. A method according to claim 2, further comprising:

filtering the input analog signal prior to the sampling.

5. A method according to claim 1, wherein the digital modulator outputs the complex numbers associated with respective of N independently modulated time-frequency cells used to transmit the temporal signals.

6. A method according to claim 1, wherein the digital modulator is one of an OFDM (Orthogonal Frequency Division Multiplexing) or COFDM (Coherent Orthogonal Frequency Division Multiplexing) modem.

7. A method according to claim 1, wherein the digital modulator comprises a single-carrier modem.

8. A method according to claim 1, wherein the input analog signal is an audio or speech signal.

9. A device for transmitting an analog signal comprising:

an input receiving said analog signal;

a sampling module configured to sample said analog signal at a predetermined frequency to generate a sampled analog signal;

a converting module configured to convert the sampled analog signal into complex numbers such that two successive samples of said sampled analog signal respectively form a real part and imaginary part of a respective complex number;

an interleaving module configured to disperse the complex numbers in a time-frequency space; and

a digital modulator configured to modulate the dispersed complex numbers into temporal signals and to output the temporal signals for transmission.

10. A device according to claim 9, further comprising:

a pre-processor configured to pre-process the sampled analog signal prior to the conversion.

11. A device according to claim 10, wherein the pre-processor performs at least one of pre-accentuation, linear distortion, or dynamic compression of the sampled analog signal.

12. A device according to claim 10, further comprising:

a filter configured to filter the input analog system prior to the sampling.

13. A device according to claim 9, wherein the digital modulator outputs the complex numbers associated with respective of N independently modulated time-frequency cells used to transmit the temporal signals.

14. A device according to claim 9, wherein the digital modulator is one of an OFDM (Orthogonal Frequency Division Multiplexing) or COFDM (Coherent Orthogonal Frequency Division Multiplexing) modem.

15. A device according to claim 9, wherein the digital modulator comprises a single-carrier modem.

16. A device according to claim 9, wherein the input analog signal is an audio or speech signal.

17. A device for transmitting an analog signal comprising:

means for inputting said analog signal;

means for sampling said analog signal at a predetermined frequency to generate a sampled analog signal;

means for converting the sampled analog signal into complex numbers such that two successive samples of said sampled analog signal respectively form a real part and imaginary part of a respective complex number;

means for dispersing the complex numbers in a time-frequency space; and

means for modulating the dispersed complex numbers through a digital modulator into temporal signals and outputting the temporal signals for transmission.

18. A device according to claim 17, further comprising:

means for pre-processing the sampled signal prior to the converting.