Wireless audio transmission system

• US 6,993,283 B1
• Filed: 07/16/2001
• Issued: 01/31/2006
• Est. Priority Date: 07/16/2001
• Status: Expired due to Fees

• Current Assignee: Nasaco Electronics Pte Limited
• Original Assignee: Nasaco Electronics Pte Limited
• Inventors: Yan Kwan, So, Ka Ming, Wu
• Primary Examiner(s): Hong, Harry S.
• Assistant Examiner(s): Nguyen, Quynh H.
• Application Number:
  US09/905,815
• Time in Patent Office: 1,660 Days
• Field of Search: 455/3.01, 455/507, 725/18, 725/62, 375/240.02
• US Class Current: 455/3.01
• CPC Class Codes: H04H 20/72 of terrestrial networks
• CPC Class Codes: H04L 25/4904 using self-synchronising codes, e.g. split-phase codes
• CPC Class Codes: H04L 25/4906 using binary codes

Abstract

A wireless transmission and reception system to convey analog signals within a local transmission area. The wireless transmission system includes a first encoder to receive an analog signal, to digitize the analog signal, and to compress the digitized analog signal using MP-3 compression; a modulator to modulate a carrier signal with the compressed digitized analog signal; and a transmitter for wireless transference of the modulated RF carrier. The reception system has a receiver to acquire the modulated carrier signal; demodulator to extract the compressed digitized analog signal from the modulated carrier signal; and a first decoder to decompress the compressed digitized analog signal using MP-3 decompression and to convert the digitized analog signal to a reproduction of the analog signal.

Claims

1. A wireless audio transmission and reception system comprising

a first encoder to receive an analog signal, to digitize said analog signal, and to compress the digitized analog signal using MP-3 compression;

a frame formatter in communication with the first encoder to divide the compressed digitized analog signal into packets, placing synchronization patterns at a beginning of each packet assembling a number of packets into a frame; and

placing an end-of-frame pattern at an end of said frame;

a bit-stuffing circuit in communication with the frame formatter to insert bits into any frame having insufficient transitions, whereby said insufficient transitions cause errors in receiving the compressed digitized analog signal;

a demodulator in communication with said bit stuffing circuit to synchronize and extract the compressed digitized analog signal from a carrier signal modulated with said compressed digitized analog signal;

a frame remover in communication with the demodulator to remove synchronization patterns from a beginning of each packet of the compressed digitized analog signals and end-of-frame patterns from an end of each frame of packets of the compressed digitized analog signals; and

a bit-extractor circuit in communication with said frame remover to remove bits inserted into the compressed digitized analog signal to restore original transitions of the compressed digitized analog signal.

2. The system of claim 1 further comprising a second encoder in communication with said first encoder to encode the frames of the compressed digitized analog signal to a non-return-to-zero invert-on-zeros (NRZI) coding.

3. The system of claim 1 further comprising a second decoder placed in communication with the demodulator and the to restore a NRZI encoded, compressed digitized analog signal to the compressed digitized analog signal.

4. The system of claim 1 wherein the carrier frequency is at least 900 MHz.

5. The system of claim 1 wherein a compression ratio of the digitized analog signal to the compressed digitized analog signal is from approximately 8:

1 to approximately 96;

1 and is determined by a quality of audio reproduction of the analog signal.

19. The system of claim 1 further comprising a modulator in communication with the first encoder to receive the compressed digitized analog signal and to modulate a carrier frequency with the compressed digitized analog signal.

20. The system of claim 19 further comprising

a transmitter in communication with the modulator to transfer the modulated carrier signal wirelessly;

and a receiver to receive the wirelessly transmitted modulated carrier signal.

21. The system of claim 1 further comprising a first decoder in communication with the bit extractor to decompress the compressed digitized analog signal using MP-3 decompression and to convert said digitized analog signal to a reproduction of the analog signal.

6. A wireless audio transmitter system comprising

a first encoder to receive an analog signal, to digitize said analog signal, and to compress the digitized analog signal using MP-3 compression;

a frame formatter in communication with the first encoder to divide the compressed digitized analog signal into packets placing synchronization patterns at a beginning of each packet, assembling a number of the packets to form a frame and placing an end-of-frame pattern at an end of said frame;

a bit-stuffing circuit in communication with the frame formatter to insert bits into any frame having insufficient transitions whereby said insufficient transitions cause errors in receiving the compressed digitized analog signal.

7. The system of claim 6 further comprising a second encoder to encode the frames of the compressed digitized analog signal to a non-return-to-zero invert-on-zeros (NRZI) coding.

8. The system of claim 6 wherein the carrier frequency is at least 900 MHz.

9. The system of claim 6 wherein a compression ratio of the digitized analog signal to the compressed digitized analog signal is from approximately 8:

1 to approximately 96;

1 and is determined by a quality of audio reproduction of the analog signal.

22. The system of claim 6 further comprising:

a modulator in communication with the first encoder to receive the compressed digitized analog signal and to modulate a carrier frequency with the compressed digitized analog signal; and

a transmitter in communication with the modulator to transfer the modulated carrier signal wirelessly.

10. A wireless audio receiver system comprising

a demodulator in communication with said bit stuffing circuit to synchronize and extract a compressed digitized analog signal from a carrier signal modulated with said compressed digitized analog signal;

a frame remover in communication between the demodulator and the first decoder to remove synchronization patterns from a beginning of each packet of the compressed digitized analog signals and end-of-frame patterns from an end of a frame of packets of the compressed digitized analog signals; and

a bit-extractor circuit in communication frame remover to remove bits inserted into the compressed digitized analog signal to restore original transitions of the compressed digitized analog signal.

11. The system of claim 10 further comprising a second decoder placed in communication the demodulator to restore a NRZI encoded, compressed digitized analog signal to the compressed digitized analog signal.

12. The system of claim 10 wherein the carrier frequency is at least 900 MHz.

13. The system of claim 10 wherein a compression ratio of the digitized analog signal to the compressed digitized analog signal is from approximately 8:

1 to approximately 96;

1 and is determined by a desired quality of audio reproduction of the analog signal.

23. The system of claim 10 further comprising a receiver to receive a wirelessly transmitted modulated carrier signal.

24. The system of claim 10 further comprising a first decoder in communication with the demodulator to decompress the compressed digitized analog signal using MP-3 decompression and to convert said digitized analog signal to a reproduction of an analog signal.

14. A method for wireless transmission of an analog signal comprising the steps of:

acquiring the analog signal;

digitizing said analog signal;

compressing the digitized analog signal according to an MP-3 encoding algorithm;

forming frames of the compressed digitized analog signal by the steps of;

assembling a plurality of bytes of the compressed digitized analog signal to create packets,

placing a synchronization pattern at a beginning of each packet,

assembling a plurality of said Packets to form frames, and

placing an end-of-frame pattern at an end of each frame;

inserting additional bits within any frame having insufficient transitions, whereby said insufficient transitions cause errors in receiving the compressed digitized analog signal;

demodulating a carrier signal modulated with said compressed digitized analog signal to extracted the compressed digitized analog signal;

removing frames from the compressed digitized analog signal by;

removing synchronization patterns from a beginning of each packet, and

removing an end-of-frame pattern from each from an end of each frame; and

extracting bits inserted to the compressed digitized analog signal to restore original transitions of the compressed digitized analog signal.

15. The method of claim 14 further comprising the step of:

encoding the compressed digitized analog signal to an NRZI format.

16. The method of claim 14 further comprising the step of:

decoding an NRZI encoded, compressed, and digitized analog signal to restore the compressed digitized analog signal.

17. The method of claim 14 wherein the carrier signal is at least 900 MHz.

18. The method of claim 14 wherein a compression ratio of the digitized analog signal to the compressed digitized analog signal is from approximately 8:

1 to approximately 96;

1 and is determined by a desired quality of audio reproduction of the analog signal.

25. The method of claim 14 further comprising the step of:

decompressing the compressed digitized analog signal according to an MP-3 decoding algorithm; and

converting the digitized analog signal to a reproduced analog signal.