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Results of the analytical analysis to assess the effect of the ultra-wideband (UWB) emissions on the [universal mobile telecommunication system (UMTS) and code division multiple access systems (CDMA-450)] are presented. The (UMTS and CDMA-450 systems) normalized range and normalized capacity degradation are evaluated. A free-space propagation model is used to calculate the UWB signal power that interferes with both mobile systems. It is shown that, for the case of a single UWB transmitter, the UMTS can easily tolerate UWB interference when the UWB equivalent isotropically radiated power (EIRP) is -92.5 dBm/MHz or less for a distance between the UWB transmitter and the UMTS mobile of 1 m or higher. Also, it is shown that, for the case of multi-UWB transmitters, the UMTS can easily tolerate the UWB interference when the UWB EIRP is -94.5 dBm/MHz. For the single UWB transmitter case, the CDMA-450 downlink can tolerate UWB interference when the UWB power density is in the order of -106 dBm/MHz. For the case of multi-UWB transmitters, the power density that can be tolerated by the downlink of the CDMA-450 system is in the order of -108 dBm/MHz. Index Terms--Code division multiple access systems (CDMA-450), macrocell normalized capacity, macrocell normalized range, ultra-wideband (UWB), universal mobile telecommunication system (UMTS).

Impulsive noise is known to be one of the most damaging types of wideband interference present in wireless communications systems, such as Universal Mobile Telecommunications Systems, Bluetooth, and Digital Video Broadcasting-Terrestrial. In order to quantify how impulsive noise degrades the quality of service (QoS) of a particular system and to evaluate the electromagnetic compatibility (EMC) requirements of a practical receiver under realistic impulsive noise conditions, it is necessary to use a flexible and modular impulsive noise generator. The primary objective of this paper is to present a low-complexity and highly flexible impulsive noise generator whose software module is implemented in a digital signal processor. In contrast to existing commercial equipment, the software implementation preserves the statistical characteristics of the measured impulsive noise parameters. In the proposed implementation, the generator presents two levels of flexibility that make it especially suitable for performing QoS tests and EMC conformance testing in realistic impulsive noise scenarios. First, the application is independent of the noise source under study. Second, the modularity of the testbed makes the generation of impulsive interference in different frequency bands possible. Experimental results confirm the feasibility and achievable performance of the proposed testbed. Index Terms--Digital signal processor (DSP), electromagnetic compatibility (EMC), impulsive noise, non-Gaussian noise, quality of service (QoS), testbed.

Byline: Bazil Taha Ahmed (1), Miguel Calvo Ramon (1), Leandro Haro Ariet (1) Keywords: W-CDMA; uplink capacity; shadowing Abstract: The uplink capacity and the interference statistics (mean and variance) of the sectors of the cigar-shaped W-CDMA microcell are studied. A model with eighteen sectors is used to analyze the uplink. The microcells are assumed to exist in a long tunnel with at least nine base stations. The hybrid model of propagation is used in the calculations. The capacity and the interference statistics of the sectors are studied in terms of the most important parameters: sector radius, specific attenuation factor, antenna sidelobe levels, bend losses and the power control standard deviation error. Author Affiliation: (1) Departamento Sistemas, Senales y Radiocomunicaciones, ETSI Telecomunicacion, Universidad Politecnica de Madrid, Ciudad Universitaria, Madrid, 28040, Spain Article History: Registration Date: 01/01/2004

The results of an extensive study on analog PAL signals interfered with by digital DVB-T signals are presented in this paper. The study covers a theoretical evaluation of the interference problems, field and laboratory measurements, and even a national survey among TV installation companies. The field measurements are reported in part I of the paper. These measurements explain the origin of co-channel and some of the adjacent channel interference problems. However, some customers reported interference in areas where the field measurements showed that the protection ratios for PAL signals interfered with by DVB-T adjacent channel signals were met. As these customers lived in flats in multistory buildings with Master Antenna TV (MATV) installations the study was extended to analyze the role of these installations in the interference problems. As will be seen, it has been found that part of the interference problems are due to the amplifiers of the MATV installations in buildings. These amplifiers, designed to operate in an analog scenario, are not prepared to cope with adjacent channel DVB-T signals. The nonlinear effects of the amplifiers give rise to intermodulation problems. The ITU-R recommendations [1] recognize that the presence of non linear amplifiers at the receiver could be a source of problems and that higher protection ratios may be needed. However, no value of the required increase of the protection ratios is given in the recommendations. As result of the laboratory tests of commercial amplifiers conducted in the study presented in this report, it has been found that an increase of the protection ratios between 12 to 16 dB would be needed to avoid a significant degradation of the PAL TV signal in these amplifiers. It has also been found that most of the interference situations are not due just to the fact of the interfering signal being a DVB-T format but that the signal amplitude of any significant signal in the passband of the filter will cause interference. Therefore, MATV system distribution needs planning factors associated with the distribution of any signals near the main signal. To be able to generalize the conclusions and to evaluate the importance of the interference problems a survey among companies who install communal telecommunication infrastructure in Spain was conducted. The results of this poll are present in Section HI. Index Terms--Adjacent-channel, co-channel, digital television, DVB-T, interference, measurement.

This paper presents the results of a study covering measurement and characterization of the wide-band impulsive noise present in a digital TV radio channel. Measurements were conducted at a frequency of 762 MHz in different outdoor and indoor environments using vertical and horizontal polarization. The measurement system was built on commercial equipment only. The calibration process, which is an important stage of this kind of measurements, is described. To analyze the measurements the impulsive noise has been modeled as a pulse train where the pulse amplitude, pulse duration and elapsed time between pulses are considered random variables. It has been found that the pulse duration and elapsed time between pulses is not dependent on the antenna polarization while the pulse amplitude is, especially in the case of the noise generated by a fluorescent lamp. It has also been found that the pulse duration of the noise measured in the outdoor environments presents some clustering features and is correlated with the pulse amplitudes. This correlation may be caused by a RF noise bandwidth that is larger than the bandwidth of the measurement system. The noise in busy streets presents larger pulse durations, larger amplitude, and shorter elapsed time between pulses that the noise measured in a pedestrian area. Several statistical tests have been done to find the distribution function that best fits these random variables. Power Rayleigh, lognormal, exponential, Poisson, and Gamma distributions have been tested. According to the assessment carried out, none of the distribution functions is adequate to model the pulse amplitudes or the elapsed time between pulses, while the pulse duration seems to be Gamma distributed. Index Terms - Digital TV, electromagnetic radiative interference, impulse noise, noise measurement, UHF measurements.