SYSTEM AND METHOD OF AN IN-BAND MODEM FOR DATA COMMUNICATIONS OVER DIGITAL WIRELESS COMMUNICATION NETWORKS

• US 20090304057A1
• Filed: 06/03/2009
• Published: 12/10/2009
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: SGRAJA, CHRISTIAN, PIETSCH, CHRISTIAN, HUANG, PENGJUN, LEUNG, NIKOLAI K.N., WERNER, MARC W., JOETTEN, CHRISTOPH A., GRANZOW, WOLFGANG
• Granted Patent: US 8,958,441 B2
• Time in Patent Office: Days
• US Class Current: 375/222
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1858 Transmission or retransmission of more than one copy of acknowledgement message
• CPC Class Codes: H04L 1/189 Transmission or retransmission of more than one copy of a message

Abstract

A system is provided for transmitting information through a speech codec (in-band) such as found in a wireless communication network. A modulator transforms the data into a spectrally noise-like signal based on the mapping of a shaped pulse to predetermined positions within a modulation frame, and the signal is efficiently encoded by a speech codec. A synchronization sequence provides modulation frame timing at the receiver and is detected based on analysis of a correlation peak pattern. A request/response protocol provides reliable transfer of data using message redundancy, retransmission, and/or robust modulation modes dependent on the communication channel conditions.

Claims

1. A method of controlling source terminal transmissions from a source terminal in an in-band communication system, the method comprising:

detecting a request signal at the source terminal;

transmitting a synchronization signal from the source terminal upon detection of the request signal;

transmitting a user data segment from the source terminal using a first modulation scheme; and

discontinuing transmission of the user data segment upon detection of a first received signal, wherein the first received signal indicates a successful reception of the user data segment from a destination terminal.

2. The method of claim 1 wherein the request signal is a start signal detected on a downlink.

3. The method of claim 1 wherein the request signal is a user initiated action at the source terminal.

4. The method of claim 1 wherein the request signal is a sensor signal detected at the source terminal.

5. The method of claim 1 further comprising switching to a second modulation scheme if the source terminal receives a predetermined number of a second received signal, wherein the second received signal indicates an unsuccessful reception of the user data segment from the destination terminal.

6. The method of claim 1 wherein the step of transmitting a synchronization signal is preceded by transmitting a send signal, and discontinuing transmission of the send signal upon detection of a third received signal, wherein the third received signal indicates a successful reception of the send signal from the destination terminal.

7. The method of claim 6, wherein the send signal is comprised of a synchronization signal followed by a send message.

8. An apparatus for controlling source terminal transmissions from a source terminal in an in-band communication system comprising:

a processor;

memory in electronic communication with the processor; and

instructions stored in the memory, the instructions being capable of executing the steps of;

detecting a request signal at the source terminal;

transmitting a synchronization signal from the source terminal upon detection of the request signal;

transmitting a user data segment from the source terminal using a first modulation scheme; and

discontinuing transmission of the user data segment upon detection of a first received signal, wherein the first received signal indicates a successful reception of the user data segment from a destination terminal.

9. The method of claim 8 wherein the request signal is a start signal detected on a downlink.

10. The method of claim 8 wherein the request signal is a user initiated action at the source terminal.

11. The method of claim 8 wherein the request signal is a sensor signal detected at the source terminal.

12. The method of claim 8 wherein the memory further comprises instructions, the instructions being executable to switch to a second modulation scheme if the source terminal receives a predetermined number of a second received signal, wherein the second received signal indicates an unsuccessful reception of the user data segment from the destination terminal.

13. The method of claim 8 wherein the memory further comprises instructions preceding the instructions of transmitting a synchronization signal, the instructions being executable to transmit a send signal, and discontinuing transmission of the send signal upon detection of a third received signal, wherein the third received signal indicates a successful reception of the send signal from the destination terminal.

14. The method of claim 13 wherein the send signal is comprised of a synchronization signal followed by a send message.

15. An apparatus for controlling source terminal transmissions from a source terminal in an in-band communication system comprising:

means for detecting a request signal at the source terminal;

means for transmitting a synchronization signal from the source terminal upon detection of the request signal;

means for transmitting a user data segment from the source terminal using a first modulation scheme; and

means for discontinuing transmission of the user data segment upon detection of a first received signal, wherein the first received signal indicates a successful reception of the user data segment from a destination terminal.

16. The method of claim 15, further comprising means for switching to a second modulation scheme if the source terminal receives a predetermined number of a second received signal, wherein the second received signal indicates an unsuccessful reception of the user data segment from the destination terminal.

17. The method of claim 15, further comprising means for transmitting a send signal prior to the synchronization signal, and discontinuing transmission of the send signal upon detection of a third received signal, wherein the third received signal indicates a successful reception of the send signal from the destination terminal.