Kyoung-Whoan Suh

The calculation of field strength for DTV receiver by Rec. ITU-R P.1546

We propose the methodology of field strength prediction for a digital television (DTV) receiver by virtue of Rec. ITU-R P.1546. The curves shown in this Rec. represent the point-to area field strength for 1kW effective radiated power in the 30 MHz ∼ 3000 MHz. Some computed results are illustrated here from the formulation of field strength for DTV receiver. It was shown that the error of field strength value for dense urban area (R = 30 m) is in the range of about 6.8 ∼ 11.5 % compared with the Okumura-Hata model under some conditions. In addition comparison of service distance between analog and digital TV receivers has been also illustrated. The presented method provides the predicted values of field strength for TV receiver whether transmission quality can be assured or not, and it can be also used to get the protection ratio or separated distance for frequency sharing in the same or adjacent band.

The Prediction of Field Strength for DTV Receiver in the VHF and UHF Bands

In this paper, we propose the methodology of prediction of field strength for a digital television (DTV) receiver by virtue of Recommendation ITU-R P.1546. The curves shown in this recommendation represent the point-to area field strength for 1.0 kW effective radiated power in the 30 MHz ~ 3000 MHz. Based upon the procedures described in this Recommendation, computation results are presented here from the derived formulation of field strength for DTV receiver. To show the validity of this method, some results are compared with the analysis by Okumura-Hata model and it was shown that the error of field strength is in the range of 6.9 ~ 11.5 %. The presented method provides not only the predicted values of field strength for DTV receiving area to check the quality of transmitted signal, but also an appropriate site selection for obtaining good propagation environment. In addition, it can be directly used for analyzing the protection ratio or separated distance for frequency sharing in the same band.

Derivation of Protection Ratio and its Calculation for Microwave Relay System Based upon Composite Fade Margin and Availability

In this paper, the derivation of protection ratio is newly proposed for the detailed planning of frequency coordination in microwave relay networks, and computed results for protection ratio of co-channel and adjacent channel are illustrated over the actual system and its frequency. It is shown that the suggested method based upon availability prediction can be expressed in terms of composite fade margin, interference-to-noise ratio(I/N), net filter discrimination, and system parameters. According to results, for 6.7 GHz, 60 km, 64-QAM, and I/N

A study on a comprehensive protection ratio calculation applicable to initial planning for frequency coordination in the fixed wireless networks

This paper suggests an efficient and comprehensive algorithm of protection ratio derivation and illustrates some calculated results applicable to the initial planning for frequency coordination in the fixed wireless access networks. The net filter discrimination associated with Tx spectrum mask and overall Rx filter characteristic has been also examined to show the effect of the adjacent channel interference. The calculations for co-channel and adjacent channel protection ratios are performed for the current M/W frequency band of 6.7 GHz including Tx spectrum mask and Rx filter response. The proposed method gives some advantages of an easy and systematic extension for protection ratio calculation and is also capable of applying the same concept to frequency coordination of the fixed millimeter wave networks

Interference Analysis of Wireless Systems with Arbitrary Antenna Patterns and Geographic Information in the VHF/UHF Bands

By using the radio propagation prediction of Rec. ITU-R P.1546, geographic information system, and S-I plane, we presented the methodology of interference analysis based on the minimum coupling loss, and also suggested the local coordinate system for calculating azimuth and elevation angles between the victim receiver and the interferer for an arbitrary antenna pattern. To check the presented algorithm, the map with the land-sea mixed area was taken for the given area of ×   as real geography information. Field strength, path profile, and protection ratio with maximum allowable interference level have been illustrated for radar and fixed wireless system for the assumed frequency. In addition interference power of the victim receiver was calculated asa function of azimuth and elevation angles of the interferer. The developed methodology of interference analysis in the VHF and UHF bands can be actually applied to assess interoperability as well as compatibility in the civil or military applications. Keyword : Rec. ITU-R P.1546, interference analysis, minimum coupling loss, signal-interference plane, geographic

Omnidirectional Collinear Antenna Using for Multi-Layer PCB Structure

In this paper, we proposed a collinear antenna with a stripline structure for IEEE 802.11b/g applications in ISM (Industrial, Scientific, Medical) band of 2.4~2.5 GHz, which supplements disadvantages of COCO(Coaxial Collinear) antenna and OMA(Omnidirectional planar Microstrip Antenna). By using the proposed 4-layer substrate, we obtained improved performances and advantages in production compared with the existing antenna. In order to get antenna arrays, the same phase structure is designed by alternatively connecting outer conductor to inner conductor with /2 antenna element, and the substrate of FR4 epoxy (

A Study on the Prediction of Electric Field Strength for Terrestrial TV Broadcasting by Digital Adoption

In this paper, we propose a calculation methodology of the service distance to assure the satisfactory quality of service for analogue and digital TV receivers. Using the field strength formulation for TV receiver based upon Rec. ITU-R P.1546, computational results are presented and discussed for both systems, and some important factors are reviewed in terms of the equivalent level of service, which must be kept due to ATV to DTV conversion. The presented method provides the predicted values of field strength at receiver areas to check whether transmission quality can be satisfied or not, and it can be also used for obtaining the protection ratio or separated distance from co-channel or adjacent interference signal.

A Design of New Digital Adaptive Predistortion Linearizer Algorithm Based on DFP(Davidon-Fletcher-Powell) Method

In this paper, a new linearization algorithm for DPD(Digital PreDistorter) is suggested. This new algorithm uses DFP(Davidon-Fletcher-Powell) method. This algorithm is more accurate than that of the existing algorithms, and this method renew the best-fit value in every routine with out setting the initial value of step-size. In modeling power amplifier, the memory polynomial model which can model the memory effect of the power amplifier is used. And the overall structure of linearizer is based on an indirect learning architecture. In order to verify for performance of proposed algorithm, we compared with LMS(Least Mean-Squares), RLS(Recursive Least squares) algorithm.

A Consideration for Field Strength Analysis Based on Rec. ITU-R P.1546 Applicable to ATV to DTV Conversion

In this paper, using the Rec. ITU-R P.1546 explaining a propagation prediction model in the VHF and UHF bands, we propose the analytical methodology for calculating the service distance and field strength for analogue and digital TV receivers. From the derived formulation of the receiver field strength, some computation results are presented and discussed in terms of the equivalent level of service caused by analogue to digital TV conversion. The suggested method is also applicable to the analysis of frequency coordination or compatibility from unwanted signal in VHF and UHF bands.

The improvement of VCO performance based upon in/out common frequency tuning

In this paper, we presented a K-band Voltage Controlled Harmonic Oscillator(VCHO) with novel structure. The proposed VCHO is a structure of two hair-pin resonators placed on input and output of active device. By using in/out common frequency tuning structure, the VCHO produced some advantages of the enhanced characteristics of fundamental frequency suppression as well as the improved second harmonic output power. According to measurement results, it has been shown that a VCHO provide the output power of −2.41 dBm, fundamental frequency suppression of −21.84 dBc, and phase noise of −101.44 dBc/Hz@100 kHz. In addition, output frequency range of 10.58 MHz could be obtained with a power variation of +/−0.19 dB over its frequency range with respect to the bias voltage from 0 to −10 V for the varactor diode.