Abstract | The application of adaptive antenna arrays offers several advantages for the design of new mobile communications systems. For the investigation of array processing algorithms a realistic simulation of the radio channel is required. The basic principle of a realtime channel sounder with an array frontend is presented. The inclusion of measurement data into the simulation of a communications system is discussed and examples are provided. I.

Wireless communication systems are currently being rapidly developed due to strong market demands. Unlike wireline communication, the bandwidth is very limited and is unlikely to grow significantly in the future. Hence it is necessary for both the receiving and sending entities to employ complex computations to increase the effective bandwidth of communication channels. One way to increase the effective bandwidth of a communication channel is to reduce the amount of data to be injected into the channel using data compression. Yet to provide reliable, end-to-end service, data compression needs to be lossless, adaptive, and transparent to the user. The throughput of data compression should also be in tune with the overall throughput of the system (10 Mbps - 100 Mbps) while minimizing communication delay. Since data compression and decompression need to be integrated into a compact and affordable wireless system, it is crucial that the implementation is minimized in terms of both area and...

In this paper, we present a new computationally efficient time-varying multi-path vectorial channel simulator that can be used to evaluate the performance of antenna array wireless receivers challenged by fast fading. The development of the simulator is based on the emulation of the spatio-temporal correlation properties of the vector channel. The channel is modeled as a multi-channel FIR system with time-varying coefficients which are obtained via the application of a space-time correlation shaping transformation on some independent random sequences. The various parts of the new simulator are described and channel simulation realizations are presented and commented. 1. INTRODUCTION Future wireless systems will almost certainly use adaptive antenna arrays [1] to increase capacity. An effective multi-path vector (multi-antenna) channel simulator is required for the performance analysis of communication systems via computer. The design of such a simulator must be done with great care si...

In this paper, we present a new, computationally efficient simulator for time-varying multi-path (fast fading) vector channel that can be used to evaluate the performance of antenna array wireless receivers. The development of the simulator is based on the emulation of the spatio-temporal correlation properties of the vector channel. The channel is modeled as a multi-channel FIR system with time-varying coefficients which are obtained via the application of a space-time correlation shaping transformation on some independent random sequences. The various parts of the new simulator are detailed and channel simulation realizations are presented and commented. 1 INTRODUCTION Because of the limited availability of spectrum, wireless system designers are under pressure to achieve high spectral efficiency. To this end, future wireless systems will almost certainly use adaptive antenna arrays [1]. Since performance analysis of communication systems is often done first via computer simulations...

ODMA (Opportunity Driven Multiple Access) is an optional extension of the third generation mobile communication standard called UMTS (Universal Mobile Telecommunication System). It defines a special ad-hoc network, where each mobile node that wants to communicate has to connect to the base station with the assistance of the forthcoming mobile nodes. So in this ad-hoc network the destination is xed, although the topology of the system changes in time due to the mobility of the nodes. Using ODMA technology the mobile stations beyond the border of the coverage area associated with the base stations are still able to get service. Thus the capacity of the system raises, on the other hand the base stations can work in a spectrally efficient manner over a short range. This paper assumes a user oriented point of view in describing the capacity of the system, which denotes the probability of successful calls on the two dimensional surface.

Analog frequency modulated (FM) systems o#er advantages of reliable speech quality and simplicity, whereas code division multiple access (CDMA) systems promise high capacity, resistance to multipath fading, and simplified frequency planning. In this thesis, we investigate the performance of a wireless local loop (WLL) system that uses the frequency modulation with the CDMA technique.

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