SYNCHRONIZATION OF AUDIO CHANNEL TIMING

• US 20150245306A1
• Filed: 02/21/2014
• Published: 08/27/2015
• Est. Priority Date: 02/21/2014
• Status: Active Grant

• Current Assignee: WISA Technologies Incorporated
• Original Assignee: Summit Semiconductor, LLC
• Inventors: BOEHLKE, Kenneth A.
• Granted Patent: US 9,723,580 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04J 3/0664 unidirectional timestamps
• CPC Class Codes: H04N 21/43076 of the same content streams on multiple devices, e.g. when family members are watching the same movie on different devices
• CPC Class Codes: H04N 21/43637 involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11] arrangements for wireless networking or broadcasting of information in indoor or near-field type systems H04B10/114
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones
• CPC Class Codes: H04R 5/04 Circuit arrangements, e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments combinations of amplifiers H03F3/68; stereophonic systems H04S
• CPC Class Codes: H04W 56/001 Synchronization between nodes

Abstract

Synchronization of plural outputs of data transported by a wireless network is facilitated by bandlimiting a sample clock signal controlling a rate at which data is processed by the network'"'"'s devices and/or bandlimiting wall time data controlling the real time for presenting a datum.

Claims

1. An audio system comprising:

(a) a first listener including;

(i) a wall clock maintaining a wall time for occurrence of an event, said wall time updated by data transmitted by a master clock and received by said first listener;

(ii) a sample clock recoverer retrieving a sample clock from data received by said first listener from a talker, said sample clock regulating a processing rate for a datum included in said data received from said talker; and

(iii) a frequency filter bandlimiting said sample clock output by said sample clock recoverer; and

(iv) a transmitter transmitting said bandlimited sample clock; and

(b) a second listener arranged to receive said transmitted bandlimited sample clock and use said bandlimited sample clock to regulate processing data received from said talker.

2. The audio system of claim 1 wherein said frequency filter comprises a low band width phase locked loop connected to receive said sample clock output by said sample clock recoverer.

3. The audio system of claim 1 wherein the first listener further comprises a frequency filter attenuating a frequency of said updating data received from said master clock.

4. The audio system of claim 3 wherein said updating data received from said master clock comprises a timing synchronization function datum.

5. The audio system of claim 3 wherein said updating datum received from said master clock comprises a precision time protocol datum.

6. An audio system comprising:

(a) a first listener including;

(i) a wall clock maintaining a wall time for occurrence of an event, said wall time updated by a data transmitted by a master clock and received by said first listener;

(ii) a frequency filter bandlimiting said updating data received from said master clock and said wall time; and

(iii) a sample clock recoverer retrieving a sample clock from data received by said first listener from a talker, said sample clock regulating a processing rate for a datum included in said data received from said talker; and

(iv) a transmitter transmitting said bandlimited wall time; and

(b) a second listener arranged to receive said bandlimited wall time and to use said bandlimited wall time to recover a sample clock from data received from said talker.

7. The audio system of claim 6 wherein said frequency filter comprises a low band width phase locked loop arranged to receive said updating data received from said master clock.

8. The audio system of claim 6 wherein said updating data received from said master clock comprises a timing synchronization function datum.

9. The audio system of claim 6 wherein said updating datum received from said master clock comprises a precision time protocol datum.

10. A method of recovering a sample clock in a network, said method comprising the steps of:

(a) generating a raw sample clock signal oscillating at a frequency determined by a datum included in a data packet; and

(b) bandlimiting said raw sample clock signal about the mean frequency of said raw sample clock signal by frequency filtering said raw sample clock signal.

11. A method of recovering a sample clock in a network, said method comprising the steps of:

(a) bandlimiting said raw wall time signal about the mean frequency of said raw wall time signal by frequency filtering said raw wall time signal; and

(b) generating a sample clock signal oscillating at a frequency determined by a datum included in a data packet and said bandlimited raw wall time signal.

12. The method of recovering a sample clock of claim 11 further comprising the step of frequency filtering said sample clock signal.