Methods and apparatus for wireless transmission using multiple description coding
View Patent ↗A multiple description coder generates a number of different descriptions of a given portion of a signal in a wireless communication system, using multiple description scalar quantization (MDSQ) or another type of multiple description coding. The different descriptions of the given portion of the signal are then arranged into packets such that at least a first description of the given portion is placed in a first packet and a second description is placed in a second packet. Each of the packets are then transmitted using a frequency hopping modulator, and the hopping rate of the modulator is selected or otherwise configured based at least in part on the number of descriptions generated for the different portions of the signal. For example, in an embodiment in which two descriptions are generated for each portion of the signal, a first description for a current one of the portions of the signal is placed in a current packet along with a second one of the descriptions for a previous portion of the signal, and the frequency hopping rate of the modulator is doubled relative to a hopping rate used for single description transmission.
1. A method of processing a signal for transmission in a wireless communication system, the method comprising the steps of:
encoding the signal in a multiple description coder which generates a plurality of different descriptions of a given portion of the signal;
arranging the different descriptions of the given portion of the signal into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
transmitting each of the packets using a frequency hopping modulator, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein the hopping rate of the frequency hopping modulator is selected such that a transmission delay of the system is not increased as a result of the transmission of the plurality of descriptions relative to a transmission delay of the system for single description transmission.
2. The method of claim 1 wherein the multiple description coder comprises a multiple description coder configured to implement multiple description scalar quantization (MDSQ).
3. The method of claim 1 wherein the multiple description coder comprises a multiple description adaptive differential pulse code modulation (ADPCM) coder.
4. The method of claim 1 wherein each of the portions of the signal corresponds to a designated segment of the signal having a particular time duration.
5. The method of claim 1 wherein the signal comprises a speech signal.
6. The method of claim 1 wherein the wireless communication system comprises a cordless telephone system.
7. The method of claim 1 wherein the frequency hopping modulator is configured such that each of the packets is transmitted using a different frequency.
8. A method of processing a signal for transmission in a wireless communication system, the method comprising the steps of:
encoding the signal in a multiple description coder which generates a plurality of different descriptions of a given portion of the signal;
arranging the different descriptions of the given portion of the signal into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
transmitting each of the packets using a frequency hopping modulator, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein the hopping rate of the frequency hopping modulator is selected as twice a frequency hopping rate of the modulator used for transmission of a single description of the given portion of the signal.
9. A method of processing a signal for transmission in a wireless communication system, the method comprising the steps of:
encoding the signal in a multiple description coder which generates a plurality of different descriptions of a given portion of the signal;
arranging the different descriptions of the given portion of the signal into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
transmitting each of the packets using a frequency hopping modulator, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein a packet size for the first and second packets is selected as one-half a packet size used for transmission of a single description of the given portion of the signal.
10. A method of processing a signal for transmission in a wireless communication system, the method comprising the steps of:
encoding the signal in a multiple description coder which generates a plurality of different descriptions of a given portion of the signal;
arranging the different descriptions of the given portion of the signal into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
transmitting each of the packets using a frequency hopping modulator, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein the encoding step generates two descriptions for each of a plurality of different portions of the signal, with a first one of the descriptions for a current one of the portions of the signal being placed in a current packet along with a second one of the descriptions for a previous portion of the signal.
11. An apparatus for processing a signal for transmission in a wireless communication system, the apparatus comprising:
a multiple description coder operative to generate a plurality of different descriptions of a given portion of the signal, the different descriptions of the given portion of the signal being arranged into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
a frequency hopping modulator having an input coupled to an output of the multiple description coder and operative to configure the packets for transmission, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein the hopping rate of the frequency hopping modulator is selected such that a transmission delay of the system is not increased as a result of the transmission of the plurality of descriptions relative to a transmission delay of the system for single description transmission.
12. The apparatus of claim 11 wherein the multiple description coder comprises a multiple description coder configured to implement multiple description scalar quantization (MDSQ).
13. The apparatus of claim 11 wherein the multiple description coder comprises a multiple description adaptive differential pulse code modulation (ADPCM) coder.
14. The apparatus of claim 11 wherein each of the portions of the signal corresponds to a designated segment of the signal having a particular time duration.
15. The apparatus of claim 11 wherein the signal comprises a speech signal.
16. The apparatus of claim 11 wherein the wireless communication system comprises a cordless telephone system.
17. The apparatus of claim 11 wherein the frequency hopping modulator is configured such that each of the packets is transmitted using a different frequency.
18. An apparatus for processing a signal for transmission in a wireless communication system, the apparatus comprising:
a multiple description coder operative to generate a plurality of different descriptions of a given portion of the signal, the different descriptions of the given portion of the signal being arranged into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
a frequency hopping modulator having an input coupled to an output of the multiple description coder and operative to configure the packets for transmission, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein the hopping rate of the frequency hopping modulator is selected as twice a frequency hopping rate of the modulator used for transmission of a single description of the given portion of the signal.
19. An apparatus for processing a signal for transmission in a wireless communication system, the apparatus comprising:
a multiple description coder operative to generate a plurality of different descriptions of a given portion of the signal, the different descriptions of the given portion of the signal being arranged into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
a frequency hopping modulator having an input coupled to an output of the multiple description coder and operative to configure the packets for transmission, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein a packet size for the first and second packets is selected as one-half a packet size used for transmission of a single description of the given portion of the signal.
20. An apparatus for processing a signal for transmission in a wireless communication system, the apparatus comprising:
a multiple description coder operative to generate a plurality of different descriptions of a given portion of the signal, the different descriptions of the given portion of the signal being arranged into packets such that at least a first description of the given portion is placed in a first packet and a second description of the given portion is placed in a second packet; and
a frequency hopping modulator having an input coupled to an output of the multiple description coder and operative to configure the packets for transmission, wherein a hopping rate of the modulator is configured based at least in part on a number of descriptions generated for each of a plurality of different portions of the signal;
wherein the multiple description coder generates two descriptions for each of a plurality of different portions of the signal, with a first one of the descriptions for a current one of the portions of the signal being placed in a current packet along with a second one of the descriptions for a previous portion of the signal.