Decoder and method for performing decoding operation using map algorithm in mobile communication system
AssigneeSamsung Electronics Co., Ltd.
InventorSeok-Chan Kim
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Abstract
A turbo decoder and a decoding method are disclosed, which use a Maximum A Posteriori (MAP) algorithm in order to perform iterative decoding. The method has the steps of sequentially receiving input data in a memory having a predetermined window size and performing a forward metric calculation for the input data so that the input data has a four window size, performing a first backward metric calculation for the input data and outputting first valid data when the data are input to the memory by twice the window size, and performing a second backward metric calculation for the input data and outputting second valid data when the data are input to the memory by three times the window size.
Claims13
A method for performing iterative decoding by a decoder in a mobile communication system using a turbo code, the method comprising the steps of:
- a) performing, via a decoding device, a forward metric calculation for sequentially input data by means of one memory corresponding in size to four times a window of predetermined size;
- b) performing, via a decoding device, a first backward metric calculation for the input data when the forward metric calculation is performed for the input data by a size of three times the window in said one memory;
- and
- c) performing, via a decoding device, a second backward metric calculation for the input data when the forward metric calculation is performed for the input data by four times the window size in said one memory.
A decoding apparatus for performing iterative decoding in a mobile communication system using a turbo code, the decoding apparatus comprising:
- one memory for outputting input data having four times a window of predetermined size in the forward direction or a backward direction;
- an alpha metric block for performing a forward metric calculation for sequentially inputting data so that the data has a size of four times the window;
- a first metric block for performing a first backward metric calculation for the input data, when a forward calculation is performed for the input data having a size of three times the window;
- and
- a second metric block for performing a second backward metric calculation for the input data, when a forward calculation is performed for the input data having four times the size of the window.
Dependencies are inferred from the claim text.