Method and apparatus for puncturing code symbols in a communications system
View Patent ↗Techniques for puncturing symbols in a communications system. S symbols are received for a frame having a capacity of N symbols, with S being greater than N. P symbols need to be punctured so that remaining symbols fit into the frame. A number of puncture distances, D 1 through DN, are computed based on S and P. A particular number of symbol punctures is determined for each computed puncture distance. P 1 through PN symbol punctures are then performed at the distances of D 1 through DN, respectively. For a more even distribution of the symbol punctures, each of the distances D 1 through DN can be selected to be greater than or equal to a minimum puncture distance Dmin defined as Dmin=└S/P┘, where └ ┘ denotes a floor operator. The symbol punctures at each computed distance can be performed together or distributed with symbol punctures at other distances.
1. A method for transmitting a frame of data comprising:
receiving a number of symbols S to be fitted into said data frame having a capacity of N symbols, where S is greater than N;
determining a number of symbols P to be punctured from among the S received symbols such that remaining unpunctured symbols fit into the frame;
computing a plurality of puncture distances D 1 through DN based on the number of received symbols S and the number of symbol punctures P, wherein each successive puncture distance is based on the ratio of received symbols S and symbol punctures P remaining after a previous puncture distance has been computed;
determining a particular number of symbol punctures to be performed for each of the plurality of puncture distances D 1 through DN, wherein P 1 through PN symbol punctures are to be performed at the puncture distances D 1 through DN, respectively, and wherein a sum of P 1 through PN is equal to P; and
performing P 1 through PN symbol punctures at the puncture distances D 1 through DN, respectively.
2. The method as recited in claim 1 further comprising:
puncturing said number of symbols S in accordance with said plurality of puncture distances to produce a punctured number of data symbols wherein said computing of at least one said plurality of puncture distances is computed by at least one of a floor operator and a ceiling operator based on the number of received symbols S and the number of symbol punctures P.
3. The method as recited in claim 1 further comprising:
coding a plurality of data bits in accordance with a coding scheme to generate said number of symbols S.
4. The method as recited in claim 1 further comprising:
interleaving said punctured number of data symbols before said transmitting.
5. An apparatus for transmitting a frame of data comprising:
means for receiving a number of symbols S to be fitted into said data frame having a capacity of N symbols, where S is greater than N;
means for determining a number of symbols P to be punctured from among the S received symbols such that remaining unpunctured symbols fit into the frame;
means for computing a plurality of puncture distances D 1 through DN based on the number of received symbols S and the number of symbol punctures P, wherein each successive puncture distance is based on the ratio of received symbols S and symbol punctures P remaining after a previous puncture distance has been computed;
means for determining a particular number of symbol punctures to be performed for each of the plurality of puncture distances D 1 through DN, wherein P 1 through PN symbol punctures are to be performed at the puncture distances D 1 through DN, respectively, and wherein a sum of P 1 through PN is equal to P; and
means for performing P 1 through PN symbol punctures at the puncture distances D 1 through DN, respectively.
6. The apparatus as recited in claim 5 further comprising:
wherein said means for computing includes means for computing at least one of said plurality of puncture distances by at least one of a floor operator and a ceiling operator based on the number of received symbols S and the number of symbol punctures P.
7. The apparatus as recited in claim 5 further comprising:
an encoder for coding a plurality of data bits in accordance with a coding scheme to generate said number of symbols S.
8. The apparatus as recited in claim 5 further comprising:
an interleaver fro interleaving said punctured number of data symbols before said transmitting.
9. An apparatus for puncturing symbols in a communication system, comprising:
means for causing a computer to receive a number of symbols S to be fitted into a data frame having a capacity of N symbols, where S is greater than N;
means for causing a computer to determine a number of symbols P to be punctured from among the S received symbols such that remaining unpunctured symbols fit into the frame;
means for causing a computer to compute a plurality of puncture distances D 1 through DN based on the number of received symbols S and the number of symbol punctures P;
means for causing a computer to determine a particular number of symbol punctures to be performed for each of the plurality of puncture distances D 1 through DN, wherein P 1 through PN symbols punctures are to be performed at the puncture distances of D 1 through DN, and wherein a sum P 1 through PN is equal to P;
means for causing a computer to perform P 1 though PN symbol punctures at the puncture distance of D 1 though DN, respectively, and
means for causing a computer to compute two puncture distances D 1 and D 2 based on the number of received symbols S and the number symbol punctures P, wherein the puncture distances D 1 and D 2 are computed as respectively:
D
1
=
⌊
S
P
⌋
and
D
2
=
⌈
S
P
⌉
where └ ┘ denotes a floor operator, and ┌ ┐ denotes a ceiling operator.
10. An apparatus for puncturing symbols for a data frame, comprising:
a receiver configured to receive a number of symbols S to be fitted into said data frame having a capacity of N symbols, where S is greater than N;
a processor configured to
determine a number of symbols P to be punctured from among the S received symbols such that remaining unpunctured symbols fit into the frame;
compute a plurality of puncture distances D 1 through DN based on the number of received symbols S and the number of symbol punctures P, wherein each successive puncture distance is based on the ratio of received symbols S and symbol punctures P remaining after a previous puncture distance has been computed;
determine a particular number of symbol punctures to be performed for each of the plurality of puncture distances D 1 through DN, wherein P 1 through PN symbol punctures are to be performed at the puncture distances D 1 through DN, respectively, and wherein a sum of P 1 through PN is equal to P; and
a symbol puncturer configured to perform P 1 through PN symbol punctures at the puncture distances D 1 through DN, respectively.
11. A processor comprising:
a processing circuit configured to
receive a number of symbols S to be fitted into said data frame having a capacity of N symbols, where S is greater than N;
determine a number of symbols P to be punctured from among the S received symbols such that remaining unpunctured symbols fit into the frame;
compute a plurality of puncture distances D 1 through DN based on the number of received symbols S and the number of symbol punctures P, wherein each successive puncture distance is based on the ratio of received symbols S and symbol punctures P remaining after a previous puncture distance has been computed;
determine a particular number of symbol punctures to be performed for each of the plurality of puncture distances D 1 through DN, wherein P 1 through PN symbol punctures are to be performed at the puncture distances D 1 through DN, respectively, and wherein a sum of P 1 through PN is equal to P; and
perform P 1 through PN symbol punctures at the puncture distances D 1 through DN, respectively.
12. A machine-readable medium having one or more instructions for puncturing a symbol stream, which when executed by a processor causes the processor to:
receive a number of symbols S to be fitted into said data frame having a capacity of N symbols, where S is greater than N;
determine a number of symbols P to be punctured from among the S received symbols such that remaining unpunctured symbols fit into the frame;
compute a plurality of puncture distances D 1 through DN based on the number of received symbols S and the number of symbol punctures P, wherein each successive puncture distance is based on the ratio of received symbols S and symbol punctures P remaining after a previous puncture distance has been computed;
determine a particular number of symbol punctures to be performed for each of the plurality of puncture distances D 1 through DN, wherein P 1 through PN symbol punctures are to be performed at the puncture distances D 1 through DN, respectively, and wherein a sum of P 1 through PN is equal to P; and
perform P 1 through PN symbol punctures at the puncture distances D 1 through DN, respectively.