MTUCI DRM- signal protection ratios for several unwanted signals. Researches and MW air tests. Защитные отношения в системе DRM при нескольких мешающих сигналах. Лабораторные исследования и эфирные эксперименты в диапазоне СЧ. Dr. Oleg V. Varlamov Research laboratory of communications transmitters Moscow Technical University of Communications and Informatics 1-st International Symposium on DRM Digital Radio Broadcasting in Russia. Moscow, Russia. 09-12 October 2007

This presentation: Research motivation Calculation method Determination of signal degradation factors DRM protection ratios for combined noise and one unwanted signal. DRM protection ratios for combined noise and several unwanted signals. Examples and results of 1017 kHz MW air test. Practical application for broadcasters Calculation software «DRM Trace» for LW and MW DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

ETSI ES 201 980 and REC. ITU-R BS.1615: Research motivation ETSI ES 201 980 and REC. ITU-R BS.1615: - Required S/N ratios for DRM reception OR: - RF protection ratios (with one unwanted signal) Real conditions at receiving point: Noise + several different (AM, DRM) unwanted signals with different frequency separation simultaneously (especially at the coverage area border) Conclusion: Calculation of protection ratios for several unwanted signals are necessary for correct coverage area planning DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Calculation method 1. «Equivalent unwanted noise power» at different wanted signals was specified for possible unwanted signals with different frequency separations. 2. All of «Equivalent unwanted noise power» from different signals are uncorrelated and may be summarize by power. 3. Total SNR must be greater then required for DRM reception. DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Determination of other signal degradation factors Transmitter distortions: SNR=30 dB; Receiver synthesizer phase noise: expensive AR-7030: max. SNR=36 dB; mass production: max. SNR=30 dB will be sufficiently Receiver intrinsic (thermal) noise; Industrial noise. SNR=27 dB 27 dB below signal 24 dB below signal SNR=24 dB SNR=21 dB and so on... DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

DRM protection ratios for combined noise and one unwanted signal. Require increase SNR and SIR on 3 dB in equal «Equivalent unwanted noise power» case DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

DRM protection ratios for combined noise and several unwanted signals. 1. Graphic or table presentation are complex or impossible at many-dimensional space. 2. After determination of all unwanted signals level, we may calculate required level of wanted signal: DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Example 1 from 1017 kHz MW air test. Spectrum at receiving point Wanted DRM A, 9 kHz Unwanted DRM A, 9 kHz Unwanted AM Unwanted TX out-of-band emission DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Example 2 from 1017 kHz MW air test. Spectrum at receiving point Wanted DRM A, 9 kHz Unwanted AM noise modulation Unwanted AM DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Results of MW air test. MW air tests verify theoretical calculations with -0,7…+0,5 dB accuracy. This work was sponsored by RTRN. DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Practical application for broadcasters Calculation software «DRM Trace» for determination of wanted signal required level was developed. Calculation software use ITU «GRWAVE» program for determination of required transmitter power for given receiving point at LW and MW. DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

User interface of «DRM Trace» calculation software DRM RX parameters DRM TX parameters Req. Signal field strength Trace parameters Req. TX power Unwanted signals menu Field strength -distance graph DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Conclusion Method of protection ratios calculation for several unwanted signals for correct coverage area planning was developed. MW air tests verify theoretical calculations. Calculation software «DRM Trace» for LW and MW was developed. DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007

Thank you for attention! vov@mtuci.ru DRM signal protection ratios for several unwanted signals. Dr. Oleg V. Varlamov, 2007