Arjang Hessamian-Alinejad

Applying Zero-Crossing Demodulation to the Bluetooth Enhanced Data Rate Mode

Short range communication systems such as Bluetooth and DECT (digital enhanced cordless telecommunications) require low-cost transceiver structures. Hence, the development of appropriate receiver techniques has been a major research topic. Particularly, analog limiter-discriminator with integrate and dump filtering (LDI) techniques have received considerable attention. With the availability of digital signal processing (DSP), the digital implementation of LDI techniques has become increasingly attractive. In order to make LDI receivers more accessible, zero-crossing detection was proposed. In this communication, the authors shall focus on a novel, yet promising, approach to digital zero-crossing detection in the intermediate frequency domain. Zero-crossing demodulation is an irregular sampling technique, which replaces the commonly employed regular, i.e. temporally equidistant sampling technique in the mentioned low-cost receivers. In this manuscript, the authors will present the theoretical aspects of zero-crossing demodulation with special focus on Bluetooth enhanced data rate (EDR). Next, the obtained performance results in terms of the bit error ratio (BER). Comparisons with theoretical bounds show the advantageous performance. Furthermore, a demonstrator concept termed HAWK shall be discussed and first measurement results will be presented

Platform Based Design of Termninals and Infrastructure Components for Cognitive Wireless Networks

Cooperation in wireless networks will facilitate a new dimension in the evolution of multimedia communications, sCtting out from the todays situation with a multitude of communication standards and radio interfaces both in the licensed and thC unlicensed domain. In order to pave the way towards cooperative networks, the deployment of cognitive wireless solutions, which will form the communication platforms, will be a key asset. In the future, we expect to see an increasingly flexible, ad-hoc utilization of the available spectrum in the unlicensed domain and a co-existence of communication standards in the licensed bands. In this communication, the authors will illustrate a platform based approach towards cognitive wireless communications. Also, the authors will present three software defined radio concepts designed by the members of the Lehrstuhl für KommunikationsTechnik, namely the HAWK (Highly Adaptable Wireless Kit), the FALCON (Flxible Access Logic for COmmunication Networks), and the MUSTANG (MUlti-STAndard single chip transceiver for the Next Generation), finally, giving an outlook on their wireless optical communication device, termed ARGOS. HAWK, FALCON, MUSTANG and ARGOS form the basis of the cognitive wireless platform, developed by the authors, termed PROMETHEUS. The setup of PROMETHEUS and its functionality shall be illustrated together with selected measurement results.

FALCON, A Software Defined Radio Transceiver Concept

In this communication, the authors present a software defined radio (SDR) transceiver design, termed FALCON. The FALCON is entirely based on a modular signal processing concept. In particular, the receiver deploys modules which process and generate log-likelihood ratio (LLR) signals, hence, providing the capability of a plug-and-play-type reconfigurability. To the best knowledge of the authors, such a reconfigurability approach has not yet been pursued as consequently before. The authors present their reconfigurability approach in this communication. The FALCON currently deploys commercial radio frequency (RF) front-ends provided by Atmel, analog and interface boards developed and implemented by the authors and DSP starter kits (DSK) with TI TMS320C6416 DSPs, provided by Texas Instruments. The hardware/software integration has been done in the laboratory of the authors as well as the development of all the signal processing modules, which have been realized in C language tailored for the TMS320C6416 DSPs (digital signal processors). The authors describe the FALCON and present measurement results. For an easy comparison of these results with widely published simulation results the authors consider UMTS/W-CDMA. It is shown that the FALCON provides superb performance

On The Implementation of Regular Spatial Sampling (RSS) Beamforming for UMTS LCR-TDD

In this communication a novel beamforming scheme is presented, which is based on regular spatial sampling (RSS) of signals. RSS beamforming allows low-complexity algorithms for smart antennas, while at the same time improving the performance of those systems. An implementation concept is presented, which shows the feasibility of implementing RSS beamforming on todays readily available hardware platforms

A Transceiver Concept Based on a Software Defined Radio Approach

In this communication, a software defined radio (SDR) transceiver design, termed FALCON, will be presented. The FALCON is entirely based on a modular signal processing concept; the FALCON receiver uses modules which process and generate log-likelihood ratio (LLR) signals, hence, providing the capability of a plug-and-play-type re-configurability. The authors’ view on re-configurability will be discussed in this communication. The FALCON currently deploys commercial radio frequency (RF) front-ends provided by Atmel, analogue and interface boards developed and implemented by the authors and DSP Starter Kits (DSK) based on TI TMS320C6416 DSPs (digital signal processors), which have been provided by Texas Instruments. The hardware/software integration has been done in the laboratory of the authors. Furthermore, the authors developed all signal processing modules in C language tailored for the TMS320C6416 DSPs. This paper will also illustrate measurement results obtained with the FALCON will be given. For an easy comparison of these results with widely published simulation results the authors will consider UMTS/W-CDMA. It will be shown that the FALCON provides a superb performance.