Stephan Pfletschinger

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The performance of bit-interleaved coded modulation with iterative detection (BICM-ID) depends strongly on the chosen constellation mapping. In this paper, we present an EXIT chart analysis of a number of mappings that have been designed especially for BICM-ID. This analysis reveals that all these mappings inevitably yield a bit error rate floor, which(More)
In this paper we present a novel and computationally efficient waterfilling algorithm for multiuser OFDM. This algorithm is based on the multiuser waterfilling theorem and determines the subcarrier allocation for a multiple access OFDM system. This approach maximizes the total bitrate under the constraints of user-individual power budgets. Once the(More)
In this paper, we consider the two-way relay channel with the two-phase protocol. In the first phase, two terminals simultaneously transmit their packets to the relay, creating a multiple-access channel (MAC), while in the second phase the relay sends a network-coded combination of the two packets to both terminals. We focus on the multiple-access phase and(More)
In this paper, we discuss the combination of nonbinary channel coding with higher-order modulation and MIMO transmission in the form of spatial multiplexing. In addition to the benefits of non-binary LDPC codes on the AWGN channel, we identify an inherent advantage for non-binary coding in multiple antenna schemes. By comparing binary and q-ary information(More)
We consider the performance of adaptive coding and modulation (ACM) over a fading channel for the case that the transmitter has only partial channel state information (CSI). We evaluate the degradation due to the partial CSI in terms of additionally required SNR by simulations and an analytical approximation. Then, we propose an ACM scheme with fast(More)
In this paper we propose a computationally efficient subcarrier allocation algorithm for a multiuser OFDM system suited for downlink and uplink transmission. The algorithm considers user-individual bitrate and power constraints and allocates to each user the most appropriate subcarriers in a way that the total transmit power is minimized. The bit and power(More)
In this paper, we extend the iterative demapping technique, also known as turbo demodulation, to OFDM. We first introduce an inner code which serves to remove the error floor, which is present in current iterative demapping schemes. This technique is then applied to OFDM with cyclic prefix or zeropadding. Using the EXIT chart, we illustrate the performance(More)
This paper is devoted to a novel frequency-selective link adaptation (LA) strategy developed in the WINNER Integrated Project, which aims to provide a new radio interface for future 4G wireless communication systems. For a single-user adaptation of modulation and code rate in a coded OFDM system, the presented bit-loading algorithm offers performance(More)
WINNER has been an ambitious research project aiming at identification and assessment of key technologies for Beyond 3G mobile systems. The WINNER mobile radio access network provides a system that is highly flexible and efficient and can provide a wide range of services to a multitude of users in many different environments. This paper provides a concise(More)