Demapper using floating-point representation of soft bits

1. A method comprising:

receiving, from a demapper, soft bits formatted as a fixed-point value;

converting the soft bits from the fixed-point value to a floating-point value, the floating-point value punctured to remove a bit; and

providing the converted soft bits to a buffer to enable decoding of the buffered soft bits.

2. The method of claim 1 , wherein receiving further comprises:

receiving, from the demapper, the fixed-point value as binary bits representing an integer part and a fractional part.

3. The method of claim 1 , wherein converting further comprises:

determining, based on the received soft bits, the floating-point value as a mantissa and an exponent.

4. The method of claim 1 , wherein converting further comprises:

determining an exponent based on a location of a most significant bit of the received soft bits; and

determining a mantissa using a sign bit and one or more bits adjacent to the most significant bit, the most significant bit being punctured from the mantissa to remove the bit, the floating-point value comprising the determined exponent and the determined mantissa.

5. The method of claim 1 , further comprising:

receiving, from the buffer, a block to be decoded by a forward error correction (FEC) decoder, the block comprising a plurality of floating-point values, each of the plurality of floating-point values representing soft bits.

6. The method of claim 5 further comprising:

converting the block comprising the plurality of floating-point values to another block comprising a plurality of fixed-point values.

7. The method of claim 6 , wherein converting further comprises:

inserting a bit representing a punctured bit, determining an average exponent based on a plurality of exponents, and inserting the mantissa into the fixed-point value.

8. The method of claim 7 , wherein inserting further comprises:

inserting the mantissa at a location in the fixed-point value, the location determined based on the average exponent.

9. The method of claim 8 , wherein inserting further comprises:

determining the location based on the average exponent and a scale factor representing a modulation type used during transmission of the block.

10. The method of claim 6 further comprising:

providing the other block comprising the plurality of fixed-point values to the forward error correction (FEC) decoder.

11. The method of claim 10 further comprising:

using, as the forward error correction (FEC) decoder, a convolution turbo code (CTC) decoder.

12. A system comprising:

means for receiving, from a demapper, soft bits formatted as a fixed-point value;

means for converting the soft bits from the fixed-point value to a floating-point value, the floating-point value punctured to remove a bit; and

means for providing the converted soft bits to a buffer to enable decoding of the buffered soft bits.

13. The system of claim 12 , wherein the means for converting further comprises:

means for determining, based on the received soft bits, the floating-point value as a mantissa and an exponent.

14. The system of claim 12 , wherein the means for converting further comprises:

means for determining an exponent based on a location of a most significant bit of the received soft bits; and

means for determining a mantissa using a sign bit and one or more bits adjacent to the most significant bit, the most significant bit being punctured from the mantissa to remove the bit, the floating-point value comprising the determined exponent and the determined mantissa.

15. A system comprising:

a demapper configured to provide soft bits formatted as a fixed-point value;

a first soft bit converter configured to receive, from the demapper, the soft bits formatted as the fixed-point value and to convert the soft bits from the fixed-point value to a floating-point value, the conversion including puncturing a bit of the floating-point value; and

a buffer configured to receive the converted soft bits to enable decoding of the buffered soft bits.

16. The system of claim 15 , wherein the first soft bit converter further comprises:

converting the soft bits from the fixed-point value to the floating-point value by determining an exponent based on a location of a most significant bit of the received soft bits and determining a mantissa using a sign bit and one or more bits adjacent to the most significant bit, the most significant bit being punctured from the mantissa to remove the bit, the floating-point value comprising the determined exponent and the determined mantissa.

17. The system of claim 15 further comprising:

a second soft bit converter configured to receive, from the buffer, a block to be decoded by a forward error correction (FEC) decoder, the block comprising a plurality of floating-point values, each of the plurality of floating-point values representing soft bits.

18. The system of claim 17 , wherein the second soft bit converter further comprises:

converting the block comprising the plurality of floating-point values to another block comprising a plurality of fixed-point values.

19. The system of claim 18 , wherein the second soft bit converter further comprises:

converting the block to the other block by inserting a bit representing a punctured bit, determining an average exponent based on a plurality of exponents, and inserting the mantissa into the fixed-point value; and

providing the other block comprising the plurality of fixed-point values to the forward error correction (FEC) decoder.