A Monitoring Network for Spectrum Governance

Dynamic Spectrum Access (DSA) is an exciting new technology, which has introduced a paradigm shift in spectrum access. As a result it also changes the role of the regulator. On one hand the scarce radio spectrum should be used in an optimal way, so that society is best served. On the other hand interference between users and between networks should be avoided. For that reason rules have to be defined for spectrum use. This topic is called spectrum governance. For evaluation and to check whether devices obey the rules, a monitoring system is needed. In this paper, we propose to use a fleet of mobile monitoring vehicles for this purpose.\u

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

Reliable Download Delivery in a Terrestrial DAB Network

Reliable file transfer is important in broadcast networks. In this paper, we have investigated if it is useful to extend the DAB standard with Fountain codes. To evaluate this, results from measurements in a live Single Frequency Network (SFN) were used. Our results show that the existing error correction algorithms provide already reliable file delivery, so there is no need to extend the DAB standard

Modulation-Index Estimation in a Combined CPM/OFDM Receiver

In this paper we develop a blind modulation-index estimator for\ud a combined CPM/OFDMReceiver. The performance of the estimator\ud in an AWGN channel is assessed by simulation and analysis\ud and its suitability for our receiver is established

A (Simplified) Bluetooth Maximum a Posteriori Probability (Map) Receiver

In our software-defined radio project, we aim at combining two standards luetooth and HIPERLAN/2. The HIPERLAN/2 receiver requires more computational power than Bluetooth. We choose to use this computational power also for Bluetooth and look for more advanced demodulation algorithms such as a maximum a posteriori probability (MAP) receiver. The paper discusses a simplified MAP receiver for Bluetooth GFSK signals. Laurent decomposition provides an orthogonal vector space for the MAP receiver. As the first Laurent waveform contains the most energy, we have used only this waveform for our (simplified) MAP receiver. This receiver requires a E/sub b//N/sub 0/ of about 11 dB for a BER of 10/sup -3/, required by the Bluetooth standard. This value is about 6 dB better than single bit demodulators. This performance is only met if the receiver has exact knowledge of the modulation index

A Real-Time GPP Software-Defined Radio Testbed for the Physical Layer of Wireless Standards

We present our contribution to the general-purpose-processor-(GPP)-based radio. We describe a baseband software-defined radio testbed for the physical layer of wireless LAN standards. All physical layer functions have been successfully mapped on a Pentium 4 processor that performs these functions in real time. The testbed consists of a transmitter PC with a DAC board and a receiver PC with an ADC board. In our project, we have implemented two different types of standards on this testbed, a continuous-phase-modulation-based standard, Bluetooth, and an OFDM-based standard, HiperLAN/2. However, our testbed can easily be extended to other standards, because the only limitation in our testbed is the maximal channel bandwidth of 20 MHz and of course the processing capabilities of the used PC. The transmitter functions require at most 714 M cycles per second and the receiver functions need 1225 M cycles per second on a Pentium 4 processor. In addition, baseband experiments have been carried out successfully

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

Opportunistic Error Correction for WLAN Applications

The current error correction layer of IEEE 802.11a WLAN is designed\ud for worst case scenarios, which often do not apply. In this paper,\ud we propose a new opportunistic error correction layer based on\ud Fountain codes and a resolution adaptive ADC. The key part in the\ud new proposed system is that only packets are processed by the\ud receiver chain which have encountered ``good'' channel conditions.\ud Others are discarded. With this new approach, around $\frac{2}{3}$\ud of the energy consumption can be saved compared with the\ud conventional IEEE 802.11a WLAN system under the same channel\ud conditions and throughput