Forward error correction scheme for data channels using universal turbo codes
A method of providing forward error correction for data services uses a parallel concatenated convolutional code which is a Turbo Code comprising a plurality of eight-state constituent encoders wherein a plurality of data block sizes are used in conjunction with said Turbo Code. A variation uses the method in a cellular radio system. Another variation uses the method in both forward and reverse likes of a cellular radio system.
1. A method of providing forward error correction for data services in a wireless system, the method comprising:
receiving data to be transmitted in the wireless system;
segmenting the received data into data blocks of a specified size; and
turbo encoding the data blocks at a code rate of 1/3 with a parallel concatenation of at least two constituent encoders connected to one interleaver,
wherein a transfer function of one or more of the constituent encoders is:
G ( D )=[1,(1 +D+D 3 )/(1 +D 2 +D 3 )].
2. The method of claim 1 , wherein the turbo encoding is performed by two constituent encoders.
3. A system providing forward error correctable data in a wireless communication network, the system comprising:
a processor a receiving data to be transmitted and segmenting the received data into data blocks of a specified size; and
a parallel concatenation of at least two constituent encoders connected to one interleaver, the constituent encoders turbo encoding the segmented data at a code rate of 1/3, and wherein a transfer function of one or more of the constituent encoders is:
G ( D )=[1,(1 +D+D 3)/(1 +D 2 +D 3)].
4. The system of claim 3 , comprising two constituent encoders.
5. A method of encoding data to provide forward error correction for data services, the method comprising:
encoding data with a turbo code encoder comprising a plurality of eight-state constituent encoders,
wherein a plurality of data block sizes is used in conjunction with said turbo code encoder, each of the plurality of constituent encoders having a rate of 1/2 and a transfer function of G(D)=[1,(1+D+D 3 )/(1+D 2 +D 3 )], wherein D denotes unit delay in presentation of data bits to an encoder, and a first encoder of said turbo code encoder receives information bits directly, while a second encoder of said turbo code encoder receives the information bits via an interleaver so that the second encoder processes the information bits in a different order than the order in which the first encoder processes the information bits.
6. The method of claim 5 , wherein the turbo code encoder comprises two constituent encoders enabling a minimum code rate equal to 1/3.
7. The method of claim 6 , wherein the encoding includes puncturing one or more output coded bits from the two constituent encoders using the turbo code encoder, the puncturing resulting in a plurality of code rates greater than or equal to 1/3.
8. A system for encoding data to provide forward error correction for data services, the system comprising:
a turbo code encoder comprising a plurality of eight-state constituent encoders, configured to provide forward error corrected data,
wherein accepting a plurality of data block sizes, wherein each of the plurality of constituent encoders has a rate of 1/2 and a transfer function of G(D)=[1,(1+D+D 3 )/(1+D 2 +D 3 )], wherein D denotes unit delay in presentation of data bits to an encoder, and a first encoder of said turbo code encoder being arranged to receive information bits, while a second encoder of said turbo code encoder is arranged to receive the information bits via an interleaver, so that the second encoder processes the information bits in a different order than the order in which the first encoder processes the information bits.
9. The system of claim 8 , wherein the turbo code encoder comprises two of said constituent encoders enabling a minimum code rate equal to 1/3.
10. A method of encoding data to provide forward error correction with a turbo code encoder for data services in a wireless system, the method comprising:
segmenting data into data blocks, each data block having a predetermined data block size; and
encoding the data block to provide forward error correction data,
wherein a plurality of data block sizes is used with the turbo code encoder,
wherein the encoding step comprises:
generating an information bit;
encoding the data block to generate a first convolutionally encoded parity bit using a 1/2 rate transfer function of G(D)=[1,(1+D+D 3 )/(1+D 2 +D 3 )];
interleaving the segmented data block to generate interleaved data; and
encoding the interleaved data to generate a second convolutionally encoded parity bit using the 1/2 rate transfer function of G(D)=[1,(1+D+D 3 )/(1+D 2 +D 3 )].
11. The method of claim 10 , wherein the turbo code encoder has a code rate of 1/3.
12. The method of claim 10 , wherein the forward error correction data comprises the information bit, first convolutionally encoded parity bit and the second convolutionally encoded parity bit.
13. The method of claim 10 , wherein the interleaving comprises adapting interleaving depth in response to size of the segmented data block.
14. A system for encoding data to provide forward error correction for data services, in a wireless system, the system comprising:
a processor adapted to segment data into data blocks, each data block having a predetermined data block size; and
a turbo code encoder configured to be used with a plurality of data block sizes and to encode the data block to provide forward error correction data, and generate an information bit by:
encoding the data block to generate a first convolutionally encoded parity bit using a 1/2 rate transfer function of G(D)=[1,(1+D+D 3 )/(1+D 2 +D 3 )];
interleaving the segmented data block to generate interleaved data; and
encoding the interleaved data to generate a second convolutionally encoded parity bit using the 1/2 rate transfer function of G(D)=[1,(1+D+D 3 )/(1+D 2 +D 3 )].
15. The system of claim 14 , wherein the turbo code encoder has a code rate of 1/3.
16. The system of claim 14 , wherein the forward error correction data comprises the information bit, first convolutionally encoded parity bit and the second convolutionally encoded parity bit.
17. The system of claim 14 , wherein the interleaving comprises adapting interleaving depth in response to size of the segmented data block.