Jörg Kliewer

Learn More
This paper proposes a network coding approach to cooperative diversity featuring the algebraic superposition of channel codes over a finite field. The scenario under consideration is one in which two ldquopartnersrdquo - node A and node B - cooperate in transmitting information to a single destination; each partner transmits both locally generated(More)
In this paper we consider the ensemble of codes formed by a serial concatenation of a repetition code with multiple accumulators through uniform random interleavers. Based on finite length weight enumerators for these codes, asymptotic expressions for the minimum distance and an arbitrary number of accumulators larger than one are derived. In accordance(More)
We propose a joint source-channel decoding approach for multidimensional correlated source signals. A Markov random field (MRF) source model is used which exemplarily considers the residual spatial correlations in an image signal after source encoding. Furthermore, the MRF parameters are selected via an analysis based on extrinsic information transfer(More)
This paper proposes a novel distributed encoding procedure to realize codes that resemble LT codes (rateless codes for erasure correction) in both structure and performance. For the case of two sources communicating with a single sink via a common relay, this technique separately encodes k/2 symbols of information onto slightly more than k code symbols at(More)
We propose relaying strategies for uncoded two-way relay channels, where two terminals transmit simultaneously to each other with the help of a relay. In particular, we consider a memoryless system, where the signal transmitted by the relay is obtained by applying an instantaneous relay function to the previously received signal. For binary antipodal(More)
We present a novel symbol-based soft-input a posteriori probability (APP) decoder for packetized variable-length encoded source indexes transmitted over wireless channels where the residual redundancy after source encoding is exploited for error protection. In combination with a mean-square or maximum APP estimation of the reconstructed source data, the(More)
In this paper we address design and properties of an oversampled non-uniform DFT filter bank derived by an allpass frequency transform from its uniform version. The novel synthesis bank utilizes only stable FIR filters, which can be designed via closed-form expressions. The overall analysis-synthesis system leads to a near-perfect-reconstruction solution,(More)
A secret sharing scheme is a method to store information securely and reliably. Particularly, in a threshold secret sharing scheme, a secret is encoded into n shares, such that any set of at least t<sub>1</sub> shares suffice to decode the secret, and any set of at most t<sub>2</sub> &lt;; t<sub>1</sub> shares reveal no information about the secret.(More)
This paper proposes a new approach to channel code design for wireless network applications. The resulting nested codes can be decoded at different effective rates by different receivers-rates that depend on the prior knowledge possessed by each receiver; we say these codes have multiple interpretations. We have identified several applications in wireless(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)