Device and method for distortion-robust decoding
View Patent ↗A device for decoding code symbols which are interfered with a distortion during a predetermined distortion time interval includes a reliability information generator to provide reliability information based on the code symbols and a decoder to decode the code symbols into code words. The decoder is configured to decode the code symbols based on weighted reliability information, wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval.
1. A device for decoding code symbols which are interfered with a distortion during a distortion time interval, comprising:
a reliability information generator configured to provide reliability information based on the code symbols; and
a decoder configured to decode the code symbols into code words based on weighted reliability information,
wherein the weighted reliability information is generated from the reliability information by applying a first weight to the reliability information during times not coinciding with the distortion time interval and by applying a second weight different from the first weight to the reliability information during times coinciding with the distortion time interval,
wherein the distortion time interval is periodic.
2. The device of claim 1 , wherein the reliability information is provided for each bit of the code symbols as a number having a sign that indicates a state of the bit, and a magnitude that indicates a reliability of the bit for being in the indicated state.
3. The device of claim 1 , wherein the reliability information comprises one of a likelihood information, a log likelihood ratio and a probability.
4. The device of claim 1 , wherein the distortion is or is caused by a synchronization signal comprising a sequence of synchronization symbols, wherein a relative position of the synchronization symbols with respect to the code symbols is configurable.
5. The device of claim 1 , wherein the decoder comprises one of a turbo decoder, a LDPC decoder, a convolutional decoder, a decoder comprising an interleaver and a decoder exploiting reliability information.
6. The device of claim 1 , wherein the second weight is smaller than the first weight.
7. The device of claim 1 , wherein the first weight or the second weight, or both, depend on a code rate of the code symbols.
8. The device of claim 7 , wherein a ratio of the second weight and the first weight is increased when increasing the code rate.
9. The device of claim 1 , wherein the first weight or the second weight, or both, depend on a modulation constellation scheme of the code symbols.
10. The device of claim 9 , wherein a ratio of the second weight and the first weight is smaller for higher degrees of a modulation constellation scheme than for lower degrees of the modulation constellation scheme.
11. The device of claim 9 , wherein the modulation comprises one or more of a QPSK, 16QAM, 64QAM and 256QAM.
12. The device of claim 1 , further comprising:
an equalizer configured to equalize a radio signal received by the device, thereby providing an equalized signal;
a demodulator configured to demodulate the equalized signal, thereby providing demodulated symbols;
a descrambler configured to descramble the demodulated symbols, thereby providing descrambled symbols; and
a despreader configured to despread the descrambled symbols, thereby providing the code symbols to the decoder.
13. A method for distortion-robust decoding of code symbols which are interfered with a distortion during a distortion time interval, comprising:
providing reliability information based on the code symbols; and
decoding the code symbols into code words based on weighted reliability information,
wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval,
wherein the distortion time interval is periodic.
14. The method of claim 13 , wherein the reliability information is provided for each bit of the code symbols as a number having a sign that indicates a state of the bit, and having a magnitude that indicates a reliability of the bit for being in the indicated state.
15. The method of claim 13 , wherein the reliability information comprises one of a log likelihood ratio and a probability.
16. The method of claim 13 , wherein the distortion is or is caused by a synchronization signal comprising a sequence of synchronization symbols.
17. The method of claim 13 , wherein the second weight is smaller than the first weight.
18. The method of claim 13 , wherein the first weight or the second weight, or both, depend on a code rate of the code symbols.
19. The method of claim 18 , wherein a ratio of the second weight and the first weight is increased when increasing the code rate.
20. The method of claim 13 , wherein the first weight or the second weight, or both, depend on a modulation constellation scheme of the code symbols.
21. The method of claim 20 , wherein a ratio of the second weight and the first weight is smaller for higher degrees of the modulation constellation scheme than for lower degrees of the modulation constellation scheme.