High quality, controlled latency multi-channel wireless digital audio distribution system and methods

• US 20070058762A1
• Filed: 08/04/2006
• Published: 03/15/2007
• Est. Priority Date: 08/04/2005
• Status: Active Grant

• Current Assignee: WISA Technologies Incorporated
• Original Assignee: Summit Semiconductor, LLC
• Inventors: Hudson, Michael, McArthur, Kelly
• Granted Patent: US 9,237,407 B2
• Time in Patent Office: Days
• US Class Current: 375/354
• CPC Class Codes: H04H 20/28 Arrangements for simultaneous broadcast of plural pieces of information
• CPC Class Codes: H04H 20/61 for local area broadcast, e.g. instore broadcast
• CPC Class Codes: H04H 20/89 using three or more audio channels, e.g. triphonic or quadraphonic
• CPC Class Codes: H04L 12/40058 Isochronous transmission
• CPC Class Codes: H04L 2012/2841 Wireless
• CPC Class Codes: H04L 2012/2849 Audio/video appliances
• CPC Class Codes: H04S 3/008 in which the audio signals are in digital form, i.e. employing more than two discrete digital channels data reduction aspects thereof based on psychoacoustics G10L19/02

Abstract

A multichannel wireless digital audio distribution system provides for the synchronization of the output of audio data by different receiving units set to output audio data for receiver unit assigned channels. The transmitter includes parallel data respectively representing a plurality of audio data channels in each data packet. The data packets are broadcast wirelessly with predetermined packets including a timing marker. Each receiver unit receives the broadcast data packets and selects the parallel data respectively representing the receiver unit assigned audio data channel. The receiver unit outputs the selected data synchronized to the receipt of the timing marker by said receiving unit.

Claims

1. A method of operating a wireless digital audio distribution system to synchronize the output of audio data by receiving units, wherein a transmitting unit provides for the wireless packet transmission of audio data for receipt by a plurality of receiving units, said method comprising the steps of:

a) generating a sequence of audio data packets wherein each said data packet includes parallel data respectively representing a plurality of audio data channels;

b) broadcasting wirelessly, by said transmitter unit, said sequence of audio data packets, wherein said transmitter unit includes a timing marker in first predetermined ones of said audio data packets;

c) receiving wirelessly, by a predetermined one of said plurality of receiving units, said sequence of audio data packets;

d) selecting, from a second predetermined one of said audio data packets, parallel data respectively representing a predetermined one of said plurality of audio data channels; and

e) outputting, said parallel data respectively representing a predetermined one of said plurality of audio data channels synchronized to the receipt of said timing marker by said receiving unit.

2. The method of claim 1 wherein said second predetermined one of said audio data packets is one of said first predetermined ones of said audio data packets.

3. The method of claim 1 wherein said step of broadcasting further includes redundantly broadcasting said sequence of audio data packets.

4. The method of claim 3 wherein said second predetermined one of said audio data packets is exclusive of said first predetermined ones of said audio data packets.

5. The method of claim 1 wherein said method further includes the steps of:

a) detecting, by said predetermined one of said plurality of receiving units, a transmission data error in a predetermined one of said first predetermined ones of said audio data packets;

. and

b) correcting said transmission data error including selection of a predetermined one of said redundantly broadcast audio data packets in replacement of said predetermined one of said first predetermined ones of said audio data packets.

6. The method of claim 5 wherein said step of correcting includes successively performing correction by:

a) first correcting said transmission data error using forward error correction to correct errors in the audio data transferred by said predetermined one of said first predetermined ones of said audio data packets;

b) second correcting said transmission data error, where said step of first correcting fails, by replacement of said predetermined one of said audio data packets; and

c) third correcting said transmission data error, where said step of second correcting fails, by interpolation using the audio data transferred by a select one of said sequence of audio data packets to construct substitute audio data in replacement for the audio data transferred by said predetermined one of said first predetermined ones of said audio data packets, wherein said select one of said sequence of audio data packets is received by said predetermined one of said plurality of receiving units prior to said predetermined one of said first predetermined ones of said audio data packets.