| 1. |
- Bezabih, Hemdan, et al.
(författare)
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Digital Broadcasting
- 2012
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Ingår i: IEEE Vehicular Technology Magazine. - 1556-6072. ; 7:1, s. 24-30
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Hokfelt, Johan, et al.
(författare)
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A survey on trellis termination alternatives for turbo codes
- 1999
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Ingår i: Proc. IEEE Vehicular Technology Conference. - 0780355652 ; 3, s. 2225-2229
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Konferensbidrag (refereegranskat)abstract
- Numerous strategies and methods for trellis termination of turbo codes have been presented and proposed in the literature. In this paper the most common trellis termination methods are compared and their relative performances are investigated. An important observation is that the performance of a termination method is highly dependent on the particular interleaver choice. Conclusions should thus be drawn for the combination of interleaver and termination method, and not for the termination method alone. Another important conclusion is that the particular choice of termination method is not crucial for the error correcting performance, as long as certain precautions are taken regarding the choice of interleaver
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| 3. |
- Hokfelt, Johan, et al.
(författare)
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A Turbo Code Interleaver Design Criterion Based on the Performance of Iterative Decoding
- 2001
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Ingår i: IEEE Communications Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1089-7798. ; 5:2, s. 52-54
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Tidskriftsartikel (refereegranskat)abstract
- The performance of a turbo code is dependent on two code properties: its distance spectrum and its suitability to be iteratively decoded. Both these properties are influenced by the choice of interleaver used in the turbo encoder. This paper presents an interleaver design criterion that focuses on the performance of iterative decoding, based on the correlation properties of the extrinsic inputs. Interleavers designed with the proposed criterion achieve very competitive performances, both in terms of convergence rates and error correcting capabilities
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| 4. |
- Hokfelt, Johan, et al.
(författare)
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Assessing interleaver suitability for turbo codes
- 1998
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Ingår i: Proc. Nordic Radio Symposium.
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Konferensbidrag (refereegranskat)abstract
- The two major purposes of the interleaver in a turbo coding scheme are, firstly, to improve the weight distribution of the turbo code, and, secondly, to make the performance of iterative decoding as close to maximum likelihood as possible. Both these purposes should be considered when ranking and designing interleavers for turbo codes. In lack of a measure of how well the second purpose is carried out we investigate a method to assess the iterative decoding suitability of interleavers. This suitability measure is used as a complement to the weight distribution, which is an insufficient base for ranking interleavers when iterative decoding is employed. It is exemplified that with proper consideration of both interleaver tasks it is possible to single out interleaver designs which yield turbo codes with improved bit and frame error rate performances, compared to a number of other interleaver designs.
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| 5. |
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| 6. |
- Hokfelt, Johan, et al.
(författare)
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Interleaver design for turbo codes based on the performance ofiterative decoding
- 1999
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Ingår i: Proc. IEEE International Conference on Communications. - 078035284X ; 1, s. 93-97
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Konferensbidrag (refereegranskat)abstract
- The performance of a turbo code is dependent on two properties of the code: its distance spectrum and its suitability to be iteratively decoded. Both these properties are dependent on the specific interleaver used in the turbo-coding scheme. This paper describes a strategy for interleaver design that includes a criterion for the performance of iterative decoding. This criterion is based upon correlation properties of the extrinsic information, which is used as a priori inputs to the constituent decoders. Simulations comparing interleaver choices indicate an improved turbo code performance for interleavers designed with algorithms including a correlation criterion
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| 7. |
- Hokfelt, Johan, et al.
(författare)
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Interleaver structures for turbo codes with reduced storage memory requirement
- 1999
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Ingår i: Proc. IEEE Vehicular Technology Conference. - 0780354354 ; 3, s. 1585-1589
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Konferensbidrag (refereegranskat)abstract
- This paper describes two interleaver structures that reduce the memory requirement for the storage of interleaver rules. The first structure offers memory reductions of more than 50%, compared to storing the entire interleaver vector. The second structure is useful when a range of interleaver sizes are to be stored, offering memory reductions asymptotically approaching 50%. By combining the two structures, a total memory reduction of approximately 75% is achieved. This is obtained without any significant reduction of the error correcting performance of the codes
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| 8. |
- Hokfelt, Johan, et al.
(författare)
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On the Theory and Performance of Trellis Termination Methods for Turbo Codes
- 2001
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Ingår i: IEEE Journal on Selected Areas in Communications. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-0008 .- 0733-8716. ; 19:5, s. 838-847
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Tidskriftsartikel (refereegranskat)abstract
- The performance of a turbo code can be severely degraded if no trellis termination is employed. This paper investigates the implications of the choice of trellis termination method for turbo codes, and explains the origin of the performance degradation often experienced without trellis termination. An efficient method to derive the distance spectrum of turbo codes for different trellis termination methods is presented. Further, we present interleaver design rules that are tailored to each termination method. Using interleavers designed with these restrictions, we demonstrate that the performance difference between various termination methods is very small, including no trellis termination at all. For example, we demonstrate a turbo code with a 500-bit interleaver that exhibits no sign of an error floor for frame error rates as low as 10-8, even though no trellis termination is employed
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| 9. |
- Hokfelt, Johan, et al.
(författare)
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Turbo codes: Correlated extrinsic information and its impact on iterative decoding performance
- 1999
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Ingår i: Proc. IEEE Vehicular Technology Conference. - 0780355652 ; 3, s. 1871-1875
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Konferensbidrag (refereegranskat)abstract
- The performance of a turbo code is dependent on two properties of the code: its distance spectrum and its suitability to be iteratively decoded. The performance of iterative decoding depends on the quality of the extrinsic inputs; badly correlated extrinsic inputs can deteriorate the performance. While most turbo coding literature assumes that the extrinsic information is uncorrelated, we investigate these correlation properties. An iterative decoding suitability measure is presented, intended to serve as an indication on the degree of correlation between extrinsic inputs. The suitability measure can be used as a complement to the weight distribution when ranking interleavers
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| 10. |
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