SPEAKER SYNCHRONIZATION TECHNIQUE FOR WIRELESS MULTICHANNEL SOUND DATA TRANSMISSION SYSTEM

• US 20110142243A1
• Filed: 05/26/2010
• Published: 06/16/2011
• Est. Priority Date: 12/10/2009
• Status: Active Grant

• Current Assignee: Korea Electronics Technology Institute (Government of South Korea)
• Original Assignee: Korea Electronics Technology Institute (Government of South Korea)
• Inventors: Kim, Hyunsik, Lee, Younsung, Wee, Jungwook, Jeon, Wongi
• Granted Patent: US 8,503,362 B2
• Time in Patent Office: Days
• US Class Current: 381/2
• CPC Class Codes: H04H 20/47 specially adapted for stereophonic broadcast systems
• 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

Abstract

The present invention relates to sound data transmission between a wireless sound transmitter that transmits sound data received from a multimedia source, and a wireless sound speaker that outputs sound signal by receiving the sound data, and more particularly, to a method for compensation of a replay time delay between the wireless sound speakers occurring when the multichannel sound data is distributed and transmitted from the wireless sound transmitter to the multiple wireless sound speakers. The differences in the replay time points occurring between the speakers in a TDMA based multichannel wireless transmission system, are pre-compensated through the delay of the sound data in the WSDT.

Claims

1. A data transmission method in a TDMA based multichannel wireless transmission system, the method comprising:

storing multiple data having identical replay time information in each corresponding memory by transmitting the data in accordance with the input clock signal;

outputting sequentially and repeatedly the stored data one by one from the corresponding memory in accordance with the output clock signal; and

transmitting a transmit packet modulated by the output data via a corresponding wireless channel.

2. The method of claim 1, wherein the time required for transmitting sequentially one set of the transmit packets of all the sound channels is less than or equal to the replay time of the stored data in the memory.

3. The method of claim 1, wherein the memory discards the oldest stored data therein when a data is inputted in accordance with the input clock signal after all the storage spaces of the memory are occupied by data.

4. The method of claim 3, wherein if the time required for transmitting one transmit packet through the wireless channel is T, the replay time of a discarded data in the M-th memory is (M−

1)T.

5. The method of claim 4, wherein the stored data in the memory are discarded only at time point prior to the transmission of the first transmit packet in the corresponding sound channels thereof.

6. A data transmission device in a TDMA based multichannel wireless transmission system, the device comprising:

a bank comprised of multiple memories wherein multiple data having identical replay time information are received in accordance with the input clock signal and stored in the corresponding memories, and the stored data is sequentially and repeatedly outputted one by one in accordance with the output clock signal;

a modem for generating transmit packets modulated by the output data; and

a communication unit for transmitting the modulated transmit packets via corresponding wireless channel.

7. The device of claim 6, further comprising a sound channel selection unit that transmits a sound channel selection signal to the bank, wherein the sound channel selection signal enables the stored data being outputted sequentially and repeatedly from the memory one at a time.

8. The device of claim 6, wherein the memory discards the oldest stored data therein when a data is inputted in accordance with the input clock signal after all the storage spaces of the memory are occupied by data.

9. The device of claim 8, wherein if the time required for transmitting one transmit packet through the wireless channel is T, the replay time of a discarded data in the M-th memory is (M−

1)T.

10. A TDMA based multichannel wireless transmission system comprising:

a wireless sound transmitter receiving multiple data having identical replay time information in accordance with the input clock signal, storing the data into the corresponding memories, outputting sequentially and repeatedly the stored data one at a time, and transmitting the transmit packets modulated by the output data via the wireless channel; and

a plurality of wireless sound speakers for replaying sounds by receiving the transmit packets from the wireless sound transmitter.

11. The TDMA based multichannel wireless transmission system according to claim 10, wherein the wireless sound transmitter comprises:

a bank comprised of multiple memories wherein multiple data having identical replay time information is received in accordance with the input clock signal and stored in the corresponding memories and the stored data is sequentially and repeatedly outputted one by one in accordance with the output clock signal;

a modem for generating transmit packets modulated by the output data; and

a communication unit for transmitting the modulated transmit packets via the wireless channel.

12. The TDMA based multichannel wireless transmission system according to claim 11, wherein the memories discard the oldest stored data therein when a data is inputted in accordance with the input clock signal after all the storage spaces of the memories are occupied by data.

13. The TDMA based multichannel wireless transmission system according to claim 12, wherein if the time required for transmitting one transmit packet through the wireless channel is T, the replay time of a discarded data in the M-th memory is (M−

1)T.

14. A data transmission method in a TDMA based multichannel wireless transmission system, the method comprising:

conveying multiple data having identical replay time information to the corresponding delay units;

outputting data inputted to the delay unit with a predetermined time delay as assigned to each sound channel;

generating transmit packets that are modulated by the output data, respectively; and

transmitting the generated transmit packets according to the order of a predetermined sequence via the wireless channels.

15. The method of claim 14, wherein if the number of sound channels is M and the time required for transmitting one transmit packet through the wireless channel is T, the length of data delay corresponding to k-th sound channel is (M−

k)T.

16. The method of claim 15, wherein the data delay is performed only at a time point prior to the transmission of the first transmit packet in the corresponding sound channels thereof.

17. The method of claim 14, wherein the time required for transmitting sequentially one set of the transmit packets of all the sound channels is less than or equal to the replay time of the demodulated transmit packets.

18. A data transmission device in a TDMA based multichannel wireless transmission system, the device comprising:

a delay unit for outputting data inputted to the delay unit with a predetermined time delay as assigned to each sound channel;

a modem for generating transmit packets modulated by the output data of the delay unit; and

a communication unit for transmitting the modulated transmit packets via the wireless channels according to the predetermined transmission order.

19. The device of claim 18, wherein if the number of sound channels is M and the time required for transmitting one transmit packet through the wireless channel is T, the length of data delay corresponding to k-th sound channel is (M−

k)T.

20. A TDMA based multichannel wireless transmission system comprising:

a wireless sound transmitter for receiving multiple data having identical replay time point, outputting the received data with a predetermined time delay as assigned to each sound channel, and transmitting the transmit packets modulated by the output data via the wireless channels; and

at least one wireless sound speaker for replaying sounds using the received transmit packets from the wireless sound transmitter.

21. The TDMA based multichannel wireless transmission system according to claim 20, wherein the wireless sound transmitter comprises:

a delay unit for outputting data inputted to the delay unit with a predetermined time delay as assigned to each sound channel;

a modem for generating transmit packets modulated by the output data of the delay unit; and

a communication unit for transmitting the modulated transmit packets via the wireless channels.

22. The TDMA based multichannel wireless transmission system according to claim 21,

wherein if the number of sound channels is M and the time required for transmitting one transmit packet through the wireless channel is T, the length of data delay corresponding to k-th sound channel is (M−

k)T.