Channel selection requirements for Bluetooth receivers using a simple demodulation algorithm

In our Software Defined Radio (SDR) project we combine two different types of standards, Bluetooth and HiperLAN/2, on one common hardware platform. SDR system research aims at the design, implementation and deployment of flexible radio systems that are reprogrammable and re-configurable by software. Goal of our project is to generate knowledge about designing the front end of an SDR system (from the antenna signal to the channel bit stream) where especially an approach from both analog and digital perspective is essential. This paper discusses the channel selection requirements for the Bluetooth standard. The standard specifications specify only the power level of the interferers, the power level of the wanted signal and the maximum allowed Bit Error Rate (BER). In order to build a radio front-end, one has to know the required (channel) suppression of these interferers. From [1] it is known that the required SNR for a Bluetooth demodulator is 21 dB, but by which value should interferers be suppressed? This paper will validate if the SNR value needs to be used for the suppression of adjacent channels. In order to answer this question a simulation model of a Bluetooth radio front-end is built

Spectral Weighting Functions for Single-symbol Phase-noise Specifications in OFDM Systems

For the specification of phase-noise requirements for the front-end of a HiperLAN/2 system we investigated available literature on the subject. Literature differed in several aspects. One aspect is in the type of phase-noise used (Wiener phase-noise or small-angle phase noise). A Wiener phase-noise based analysis leads to contradictions with the type of analysis normally used in the solid state oscillator literature. However, a phase-noise spectrum with a Wiener phase-noise shape can be used provided that the small-angle approximation is satisfied. An other aspect is whether a Fourier Series or DFT based approach is used. The approaches use weighting functions to relate phase-noise power spectral densities to phase-noise power. The two types of analysis are presented in a unified fashion that allows easy comparison of the weighting functions involved. It can be shown that for practical purposes results are identical. Finally phase-noise specifications for the Hiper-LAN/2 case are presented

Adjacent Channel Interference in UMTS Networks

One of the purposes of receive filtering in a Universal Mobile Telecommunication System (UMTS) handset receiver is to attenuate out-of-channel interference to provide channel selectivity. A UMTS handset receiver using a receive filter adaptive on out-of-channel interference level can be more computationally efficient than a handset with a fixed receive filter provided that the hand-set operates in low out-of-channel interference conditions often enough. The UMTS Adjacent Channel Selectivity (ACS) test case requires the adaptive receive filter to provide a worst case ACS of 33 dB. An adaptive receive filter is more computationally efficient than a fixed receive filter when the required ACS is less than 23 dB, because the added complexity of measuring the out-of-channel interference is compensated for by the reduction in the required number of filter taps to achieve the ACS. Measurements of the out-of-channel interference show that currently the interference levels for which the maximum ACS of 33 dB is required are hardly ever reached in practice. For the currently measured interference levels an adaptive receive filter will be computationally more efficient than a fixed\ud receive filter 97% of the time. However, the current out-of-channel interference measurements might be on the optimistic side, because the loads of the UMTS networks are low. When these loads increase in the future, the out-of-channel interference levels may increase and the advantage in computational efficiency of the adaptive receive filter will be reduced