Axel Hübner

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— Cyclic Delay Diversity (CDD) is a simple approach to introduce spatial diversity to an Orthogonal Frequency Division Multiplexing (OFDM) based transmission scheme that itself has no built-in diversity. It also can be regarded as a Space-Time Code (STC). But in contrast to that there is no additional effort in the receiver necessary, since the different(More)
In this paper we address the extrinsic information transfer functions of inner decoders for a serially concatenated coding scheme. For the case of an AWGN channel, we give a universal proof for the fact that only inner encoders yielding an infinite output weight for a weight-one input sequence, such as recursive convolutional encoders, lead to perfect(More)
—Cyclic Delay Diversity (CDD) is a simple approach to increase the frequency selectivity of the channel as seen by the receiver in an Orthogonal Frequency Division Multiplexing (OFDM) based transmission scheme. The reason for this is that CDD inserts virtual echos. Due to the virtual multipath components carriers experience different channels if the antenna(More)
In this paper we introduce a new coding scheme - so-called laminated turbo codes. It is characterized by a block-convolutional structure that enables us to combine the advantages of a convolutional encoder memory and a block-oriented decoding method. We show that this block-convolutional structure is superior in terms of its error correction capability(More)
In this paper the impact of S-type permutors, i.e., permutors that provide a non-trivial separation, on the minimum distance of double serially concatenated convolutional codes is considered. A joint design of the outer and inner permutor is presented on the basis of a newly introduced permutor parameter - the so-called symbol span. This design guarantees(More)
The free distance of convolutional codes is the most important parameter determining their performance under good channel conditions. In this paper, we investigate the free distance properties of turbo-like codes generated by non-terminated convolutional encoders and convolutional permutors. In particular, we prove the existence of such codes whose free(More)
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