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

• US 20090306970A1
• 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: Werner, Marc W., Leung, Nikolai KN, Sgraja, Christian, Pietsch, Christian, Joetten, Christoph A., Granzow, Wolfgang, Huang, Pengjun
• Granted Patent: US 9,083,521 B2
• Time in Patent Office: Days
• US Class Current: 704/201
• CPC Class Codes: G10L 19/167 Audio streaming, i.e. formatting and decoding of an encoded audio signal representation into a data stream for transmission or storage purposes
• CPC Class Codes: H04J 3/06 Synchronising arrangements for television systems H04N5/04; bit-synchronisation H04L7/00
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/003 Adaptive formatting arrangements particular to signalling, e.g. variable amount of bits
• 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 destination terminal in an in-band communication system, the method comprising the steps of:

transmitting a start signal from a destination terminal;

discontinuing transmission of the start signal upon detection of a first received signal, wherein the first received signal indicates a successful reception of the start signal from a source terminal;

transmitting a NACK signal from the destination terminal, whereby the source terminal is constrained to respond in a first predetermined manner discontinuing transmission of the NACK signal upon detection of a successfully received source terminal data message;

transmitting a ACK signal from the destination terminal, whereby the source terminal is constrained to respond in a second predetermined manner; and

discontinuing transmission of the ACK signal after a predetermined number of the ACK signals have been transmitted.

2. The method of claim 1 wherein the start signal is comprised of a synchronization signal followed by a start message.

3. The method of claim 1 wherein the NACK signal is comprised of a synchronization signal followed by a NACK message.

4. The method of claim 1 wherein the ACK signal is comprised of a synchronization signal followed by an ACK message.

5. The method of claim 1 wherein the successfully received source terminal data message is the data message verified by a cyclic redundancy check.

6. The method of claim 1 further comprising repeating the steps based on the transmission of a predetermined number of the NACK signals without detection of a successfully received source terminal data message.

7. An apparatus for controlling source terminal transmissions from a destination 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;

transmitting a start signal from a destination terminal;

discontinuing transmission of the start signal upon detection of a first received signal, wherein the first received signal indicates a successful reception of the start signal from a source terminal;

transmitting a NACK signal from the destination terminal, whereby the source terminal is constrained to respond in a first predetermined manner;

discontinuing transmission of the NACK signal upon detection of a successfully received source terminal data message;

transmitting a ACK signal from the destination terminal, whereby the source terminal is constrained to respond in a second predetermined manner; and

discontinuing transmission of the ACK signal after a predetermined number of the ACK signals have been transmitted.

8. The apparatus of claim 7 wherein the start signal is comprised of a synchronization signal followed by a start message.

9. The apparatus of claim 7 wherein the NACK signal is comprised of a synchronization signal followed by a NACK message.

10. The apparatus of claim 7 wherein the ACK signal is comprised of a synchronization signal followed by an ACK message.

11. The apparatus of claim 7 wherein the successfully received source terminal data message is the data message verified by a cyclic redundancy check.

12. The apparatus of claim 7 wherein the memory further comprises instructions, the instructions being executable to repeat the steps based on the transmission of a predetermined number of the NACK signals without detection of a successfully received source terminal data message.

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

means for transmitting a start signal from a destination terminal;

means for discontinuing transmission of the start signal upon detection of a first received signal, wherein the first received signal indicates a successful reception of the start signal from a source terminal;

means for transmitting a NACK signal from the destination terminal, whereby the source terminal is constrained to respond in a first predetermined manner;

means for discontinuing transmission of the NACK signal upon detection of a successfully received source terminal data message;

means for transmitting a ACK signal from the destination terminal, whereby the source terminal is constrained to respond in a second predetermined manner; and

means for discontinuing transmission of the ACK signal after a predetermined number of the ACK signals have been transmitted.

14. The apparatus of claim 13, further comprising means for repeating the steps based on the transmission of a predetermined number of the NACK signals without detection of a successfully received source terminal data message.