Device and method for efficient utilization of allocated transmission medium bandwidth

• US 5,825,976 A
• Filed: 04/18/1996
• Issued: 10/20/1998
• Est. Priority Date: 12/15/1993
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Dorward, Sean Matthew, Johnston, James David, Quackenbush, Schuyler Reynier, Jayant, Nuggehally Sampath, Thompson, Kenneth Lane
• Primary Examiner(s): MacDonald, Allen R.
• Assistant Examiner(s): EDOUARD, PATRICK NESTOR
• Application Number:
  US08/634,538
• Time in Patent Office: 915 Days
• Field of Search: 395/2.38, 395/2.39, 395/2.35, 395/2.36, 395/2.37, 395/2.19, 381/31, 381/2, 371/37.4, 371/37.1, 348/409
• US Class Current: 704/229
• CPC Class Codes: H04B 1/665 using psychoacoustic properties of the ear, e.g. masking effect
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end

Abstract

An independent transport layer is used as an error correction mechanism in a method employing perceptual audio coding. The transport layer is characterized by the addition of information, via a transport header, to each of a succession of blocks of encoded program material which is independent of the information within its respective block of encoded program material. The transport header comprises information on the structure of the block. Thus, the transport header is easily separated from the digital representation of the program material and is independent of the content of the digital representation thereby providing for changing of the content of the digital representation without changing the transport layer.

Claims

1. A method comprising the steps of:

receiving a signal;

encoding at least a portion of said signal into a sequence of encoded blocks using a perceptual encoding method; and

for each encoded block of said sequence of encoded blocks, generating a transmittable block by combining a transport header with said encoded block, the content of said transport header being independent of the content of said encoded block, and said transport header containing a first set of pointers identifying a first one of said encoded blocks and a second set of pointers identifying a second one of said encoded blocks.

2. The method of claim 1 wherein said signal represents program material capable of human perception.

3. The method of claim 1 wherein said transport header includes information on the structure of said transmittable block.

4. The method of claim 1 wherein said transport header comprises:

a synchronization pattern signifying the beginning of said transmittable block; and

a set of ancillary data.

5. A method comprising the steps of:

(a) generating a first digital signal representing a perceptual stimulus, said first digital signal comprising a sequence of time blocks;

(b) receiving a second digital signal;

(c) for each time block in said sequence of time blocks;

(1) encoding said time block using a perceptual encoding method; and

(2) generating an output block comprising said encoded time block and a portion of said second digital signal; and

(d) combining said output block with a transport header to form a transmittable block, the content of said transport header being independent of the content of said output block, and said transport header containing a first set of pointers identifying a first one of said encoded time blocks and a second set of pointers identifying a second one of said encoded time blocks.

6. The method of claim 5 wherein said perceptual stimulus is an audio signal.

7. The method of claim 5 wherein said perceptual encoding method includes selecting noise threshold values based upon noise masking criteria and using said selected noise threshold values to control the coarseness of quantizing during said encoding.

8. The method of claim 5 wherein said transport header includes information on the structure of said transmittable block.

9. A method of forming a digital output signal comprising:

inputting a signal into a selective combiner, said signal being encoded according to a perceptual encoding method to generate a set of encoded blocks, each encoded block being represented by a number of bits, NU_i, the number of bits being variable from encoded block to encoded block and being less than or equal to a respective predetermined number N_i ; and

outputting a digital output signal from said selective combiner, said digital output signal comprising a set of transmittable blocks, each transmittable block of said set of transmittable blocks being formed by the combination of (1) a respective one superblock from a set of superblocks, each said superblock in said set of superblocks comprising a respective one encoded block, represented by said number of bits NU_i, from said set of encoded blocks and a number of bits of a digital signal which is less than or equal to the difference between N_i and NU_i, with (2) a respective one transport header from a set of transport headers, the content of each said transport header being independent of the content of said superblock being combined therewith, and each said transport header containing a first set of pointers identifying particular bits from said number of bits, NU_i, of a first one of said encoded blocks and a second set of pointers identifying particular bits from said number of bits, NU_i, of a second one of said encoded blocks.

10. The method of claim 9 wherein said transport header includes information on the structure of said transmittable block.

11. A method comprising the steps of:

(a) receiving a first digital signal representing a signal capable of being perceived by a human;

(b) encoding said first digital signal into a sequence of encoded blocks using a perceptual encoding method;

(c) representing each encoded block in said sequence of encoded blocks by a number of bits, NU_i, less than or equal to a predetermined number N_i, wherein N_i is a maximum number of bits for encoding the i^th encoded block;

(d) receiving a second signal;

(e) for each said encoded block, generating an N_i -bit output block comprising said encoded block and a portion of said second signal comprising no more than NA_i bits, wherein NA_i represents the difference between N_i and NU_i ; and

(f) combining said N_i -bit output block with a transport header to form a transmittable block, the content of said transport header being separate from the content of said N_i -bit output block, and said transport header containing a first set of pointers identifying particular bits from said number of bits, NU_i, of a first one of said encoded blocks and a second set of pointers identifying particular bits from said number of bits, NU_i, of a second one of said encoded blocks.

12. The method of claim 11 wherein said transport header includes information on the structure of said transmittable block.

15. The method of claim 9 or 11 in which said transport header comprises:

a synchronization pattern signifying the beginning of said transmittable block; and

a set of ancillary data.

13. A transmitter for transmitting a digital output signal comprising:

an input for receiving an audio signal;

an encoder for encoding said audio signal into a plurality of encoded blocks using a perceptual encoding method; and

a transport layer assembler for outputting said digital output signal, said digital output signal comprising a plurality of transmittable blocks, each said transmittable block being generated by combining a transport header with an individual encoded block of said plurality of encoded blocks, the content of said transport header being independent of the content of said individual encoded block, and said transport header containing a first set of pointers identifying a first one of said encoded blocks and a second set of pointers identifying a second one of said encoded blocks.

14. The transmitter of claim 13 wherein said transport header comprises:

a synchronization pattern signifying the beginning of said transmittable block;

and

a set of ancillary data.

16. An apparatus for use in transmitting a digital output signal comprising:

a transport layer assembler for receiving a first digital signal and second digital signal, said first digital signal being encoded according to a perceptual encoding method to generate a plurality of encoded blocks, each encoded block being represented by a number of bits, NU_i, the number of bits being variable from encoded block to encoded block and being no more than a respective predetermined number N_i ; and

means for transmitting said digital output signal, said digital output signal comprising a plurality of transmittable blocks, each transmittable block of said plurality of transmittable blocks being formed by the combination of (1) a respective one superblock from a plurality of superblocks, each said superblock in said plurality of superblocks comprising a respective one encoded block, represented by said number of bits NU_i, from said set of encoded blocks and a number of bits of said second digital signal which is less than or equal to the difference between N_i and NU_i, with (2) a respective one transport header from a plurality of transport of headers, the content of each transport header being separate from the content of said superblock being combined therewith, and each said transport header containing a first set of pointers identifying particular bits from said number of bits, NU_i, of a first one of said encoded blocks and a second set of pointers identifying particular bits from said number of bits, NU_i, of a second one of said encoded blocks.

17. The apparatus of claim 16 wherein each said transport header includes information on the structure of said transmittable block.

18. The apparatus of claim 16, wherein said transport header comprises:

a synchronization pattern signifying the beginning of said transmittable block; and

a set of ancillary data.

19. An arrangement for use in a receiver which receives intelligence communicated to said receiver by a transmitter, said transmitter including (a) means for receiving an input signal;

(b) means for encoding at least a portion of said input signal into a sequence of encoded blocks using a perceptual encoding method;

(c) means for outputting a digital output signal, said digital output signal comprising a set of transmittable blocks, each transmittable block of said set of transmittable blocks being formed by combining a transport header with one of said encoded blocks, the content of said transport header being independent of the content of said one encoded block, and said transport header containing a first set of pointers identifying a first one of said encoded blocks and a second set of pointers identifying a second one of said encoded blocks; and

(d) means for communicating said digital output signal to said receiver over a communication channel, said arrangement comprising;

means for receiving said digital output signal from said communication channel; and

means for decoding said digital output signal to recover said input signal.

20. The apparatus of claim 19 wherein each said transport header includes information on the structure of said transmittable block.

21. The apparatus of claim 19 wherein each said transport header comprises:

a synchronization pattern signifying the beginning of said transmittable block; and

a set of ancillary data.

22. An arrangement for use in a receiver which receives intelligence communicated to said receiver by a transmitter, said transmitter including (a) a transport layer assembler for receiving a first digital signal and second digital signal, said first digital signal being encoded according to a perceptual encoding method to generate a plurality of encoded blocks, each encoded block being represented by a number of bits, NU_i, the number of bits being variable from encoded block to encoded block and being no more than a respective predetermined number N_i ;

(b) means for outputting a digital output signal, said digital output signal comprising a plurality of transmittable blocks, each transmittable block of said plurality of transmittable blocks being formed by the combination of (1) a respective one superblock from a plurality of superblocks, each said superblock in said plurality of superblocks comprising a respective one encoded block, represented by said number of bits NU_i, from said set of encoded blocks and a number of bits of said second digital signal which is less than or equal to the difference between N_i and NU_i, with (2) a respective one transport header from a plurality of transport of headers, the content of each transport header being independent of the content of said superblock being combined therewith, and each said transport header containing a first set of pointers identifying particular bits from said number of bits, NU_i, of a first one of said encoded blocks and a second set of pointers identifying particular bits from said number of bits, NU_i, of a second one of said encoded blocks; and

(c) means for communicating said digital output signal to said receiver over a communication channel, said arrangement comprising;

means for receiving said digital output signal from said communication channel; and

means for decoding said digital output signal to recover said first digital signal and said second digital signal.

23. The apparatus of claim 22 wherein each said transport header includes information on the structure of said transmittable block.

24. The apparatus of claim 22 wherein each said transport header comprises:

a synchronization pattern signifying the beginning of said transmittable block; and

a set of ancillary data.