Rainer Schoenen

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Next generation cellular radio systems will exceed the limitations of UMTS. The convergence of data and voice traffic will be supported by a flexible OFDM-based PHY layer and an OFDMA-capable MAC layer. The long term evolution (LTE) successor of the 3G systems incorporates this. But problems concerning coverage and capacity at the cell border still remain(More)
The future cellular radio networks like 3G-LTE [1] are based on an OFDMA physical layer. The duplex scheme is preferably frequency division (FDD) because of its advantages in long range. Huge area coverage in a cost-efficient way is important problem for the early deployment. Time after time the demand in densely populated areas will grow, so a higher cell(More)
Multirate Data ow Graphs (MR-DFGs) are used for modelling iterative computations, allowing concurrency and arbitrary data rates at ports. This model is often used for signal processing algorithms. For static scheduling the iteration period bound represents the nal barrier for the computation speed, the approximation of which is often the goal of an(More)
Multihop cellular networks offer increased coverage and capacity compared to singlehop cells of the same size. This is not as huge as using more base stations (BS) instead of wireless relay nodes (RN), but by this way there is no need for a fixed network access to each node. Therefore a cost-efficient deployment is easily achieved (less CAPEX and OPEX).(More)
Many signal processing systems make use of event driven mechanisms-typically based on finite state machines (FSMs)-to control the operation of the computationally intensive (data flow) parts. The state machines in turn are often fueled by external inputs as well as by feedback from the signal processing portions of the system. Packet-based transmission(More)
A recent approach in modeling and analysis of the supply and demand in heterogeneous wireless cellular networks has been the use of two independent Poisson point processes (PPPs) for the locations of base stations (BSs) and user equipment (UE). This popular approach has two major shortcomings. First, although the PPP model may be a fitting one for the BS(More)
The focus of this paper is on studying the tradeoff between the sum efficiency and Jain’s fairness index in general resource allocation problems. Such problems are frequently encountered in wireless communication systems with M users. Among the commonly-used methods to approach these problems is the one based on the α-fair policy. Analyzing this policy, it(More)
The demand for wireless access data rates is growing exponentially at a pace where supply cannot keep up with. Wireless resources (spectrum, time, space) are limited and shared, and transmission rates cannot be improved anymore solely with physical layer innovations. On the consumer side, flat rate type tariffs have established unnecessarily high(More)
User-centric services are a growing concern. While the digital society definitely needs better quality-of-experience (QoE) for the user, his applications on smart mobile devices will continue to raise traffic in mobile radio networks by 100% per annum. Future generations of access technologies are challenged by this and the old over provisioning approach(More)