Systems and methods for communicating half-rate encoded voice frames

• US 9,924,451 B2
• Filed: 12/02/2015
• Issued: 03/20/2018
• Est. Priority Date: 12/02/2015
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Natarahjan, Harish, Aziz, Mohd Syazani b Abdul, Almasi, Andor, Corretjer, Jesus F.
• Primary Examiner(s): Patel, Parth
• Application Number:
  US14/957,336
• Publication Number:
  US 20170164271A1
• Time in Patent Office: 839 Days
• CPC Class Codes: G10L 19/005 Correction of errors induced by the transmission channel, if related to the coding algorithm
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

A method for communicating half-rate encoded voice frames. The method includes receiving, by a digital signal processor, a half-rate encoded voice frame. The method further includes determining, by the digital signal processor, a network access code. The method further includes encoding, by the digital signal processor, a network identifier based on the network access code. The method further includes scrambling, by the digital signal processor, the network identifier to generate a scrambled network identifier. The method further includes generating, by the digital signal processor, an erasure pattern. The method further includes generating, by the digital signal processor, a half-rate embedded voice code word based on the erasure pattern and the half-rate encoded voice frame. The method further includes generating, by the digital signal processor, a half-rate embedded logical data unit based on the half-rate embedded voice code word and the scrambled network identifier.

Claims

1. A method for communicating half-rate encoded voice frames, the method comprising:

receiving, by a digital signal processor, a half-rate encoded voice frame;

determining, by the digital signal processor, a network access code;

encoding, by the digital signal processor, a network identifier based on the network access code;

scrambling, by the digital signal processor, the network identifier to generate a scrambled network identifier;

generating, by the digital signal processor, an erasure pattern including a deliberately-introduced error;

generating, by the digital signal processor, a half-rate embedded voice code word based on the erasure pattern and the half-rate encoded voice frame; and

generating, by the digital signal processor, a half-rate embedded logical data unit based on the half-rate embedded voice code word and the scrambled network identifier.

2. The method of claim 1, further comprising:

transmitting, by the digital signal processor via a transceiver, the half-rate embedded logical data unit.

3. The method of claim 1, wherein receiving the half-rate encoded voice frame includes receiving a time division multiple access frame from a mobile subscriber unit.

4. The method of claim 1, wherein receiving half-rate encoded voice frame includes receiving the half-rate encoded voice frame from a voice encoder.

5. The method of claim 1, wherein scrambling the network identifier includes applying a bit mask to the network identifier using an exclusive or operation.

6. The method of claim 1, wherein generating the half-rate embedded logical data unit includes generating, by the digital signal processor, a common air interface logical data unit.

7. The method of claim 1, wherein generating an erasure pattern includes

applying, by the digital signal processor, forward error correction to a plurality of voice information vectors to generate a plurality of voice code words;

inserting, by the digital signal processor, a plurality of errors into the plurality of voice code words to generate a plurality of erred voice code words; and

applying, by the digital signal processor, a pseudorandom noise sequence to at least one of the plurality of erred voice code words.

8. The method of claim 1, further comprising:

receiving, by the digital signal processor, a second half-rate embedded logical data unit including a second scrambled network identifier and a second half-rate embedded voice code word;

decoding, by the digital signal processor, the second scrambled network identifier to generate a decoded network access code;

determining, by the digital signal processor, whether the decoded network access code is invalid;

descrambling, by the digital signal processor, the second scrambled network identifier to extract a second network identifier when the decoded network access code is invalid;

decoding, by the digital signal processor, the second network identifier to extract a second network access code;

determining, by the digital signal processor, whether the second network access code is valid;

extracting, by the digital signal processor, the second half-rate embedded voice code word from the second half-rate embedded voice message when the second network access code is valid; and

extracting, by the digital signal processor, a second half-rate encoded voice frame from the second half-rate embedded voice code word.

9. The method of claim 8, further comprising:

generating, by the digital signal processor, a second time division multiple access frame based on the second network identifier and the second half-rate encoded voice frame; and

transmitting, by the digital signal processor via a data link, the second time division multiple access frame.

10. The method of claim 8, further comprising:

generating, by the digital signal processor, an audio output from the second half-rate encoded voice frame; and

playing, via a speaker, the audio output.

11. An electronic communications device, the device comprising:

a transceiver, and

a digital signal processor electrically coupled to the transceiver and configured to

receive a half-rate encoded voice frame;

determine a network access code;

encode a network identifier based on the network access code;

scramble the network identifier to generate a scrambled network identifier;

generate an erasure pattern including a deliberately-introduced error;

generate a half-rate embedded voice code word based on the erasure pattern and the half-rate encoded voice frame;

generate a half-rate embedded logical data unit based on the half-rate embedded voice code word and the scrambled network identifier; and

transmit, via the transceiver, the half-rate embedded logical data unit.

12. The device of claim 11, further comprising:

a data port;

wherein receiving the half-rate encoded voice frame includes receiving a time division multiple access frame from a mobile subscriber unit via the data port.

13. The device of claim 11, further comprising:

a voice encoder,

wherein the digital signal processor is further configured to receive the half-rate encoded voice frame from the voice encoder.

14. The device of claim 11, wherein the digital signal processor is further configured to

receive a second half-rate embedded logical data unit including a second scrambled network identifier and a second half-rate embedded voice code word;

decode the second scrambled network identifier to generate a decoded network access code;

determine whether the decoded network access code is invalid;

descramble the second scrambled network identifier to extract a second network identifier when the decoded network access code is invalid;

decode the second network identifier to extract a second network access code;

determine whether the second network access code is valid;

extract a second half-rate embedded voice code word from the second half-rate embedded logical data unit when the second network access code is valid; and

extract a second half-rate encoded voice frame from the second half-rate embedded voice code word.

15. The device of claim 14, further comprising:

a data port,

wherein the digital signal processor is further configured to

generate a second time division multiple access frame based on the second network identifier and the second half-rate encoded voice frame; and

transmit, via the data port, the second time division multiple access frame.

16. The device of claim 14, further comprising:

a speaker,

wherein the digital signal processor is further configured to

generate an audio output from the second half-rate encoded voice frame; and

play, via the speaker, the audio output.