M.I. Spazhakin – Post-graduate Student, Department of Radio Engineering, Voronezh State Technical University; Engineer, Sector of Digital Signal Processing, Voronezh branch of JSC «IRKOS»
S.A. Slinchuk – Associate Professor, Department of Radio Engineering, Voronezh State Technical University
A.B. Tokarev – Dr. Sc. (Eng.), Professor, Department of Radio Engineering, Voronezh State Technical University; Head of Research Sector, Voronezh branch of JSC «IRKOS»
P.P. Churakov – Dr. Sc. (Eng.), Professor, Dean of Faculty «Testing, Information Technologies and Systems»,
Penza State University
Increasing the efficiency of broadband radio monitoring systems is inextricably linked with the application of multi-channel narrowband signal processing when the characteristics of modern narrowband digital communication standards must be evaluated. The aim of the processing to allocate a limited set of previously known channels allows to make the processing of channels in two stages. In the first stage, preliminary filtering, conversion to zero frequency and decimation are applied to wideband signal by digital filter bank, on the second stage - narrowband filtering of the selected set of channels. Such scheme allows to obtain an efficient distribution of computing resources between two stages, as well as to increase the frequency selectivity of narrowband channels. The article considers an example of development of a two-stage multichannel filter, which was designed for processing signals of the TETRA standard. Requirements for the frequency response of the prototype filter and the narrow-band channel filter were formulated. Comparison of the spectral characteristics of the output signals is presented at different stages of processing in both approaches. It is shown that the using of a two-stage approach, under certain conditions (the number of narrow-band channels does not exceed 64), makes it possible to obtain both increasing selectivity in the neighboring channel and a reduction of computing resources in the FPGA implementation of multi-channel processing. The results of simulation show that in the case of a significant frequency mismatch, the two-stage approach provides an increasing of the dynamic range by more than 10 dB without degrading the bit error rate. A comparative evaluation of the use of computing resources for both approaches, obtained during the FPGA project trace, showed a 30% reduction in the spending of multipliers and 40% of memory blocks in the case of a two-step approach. Thus, two-stage processing is much more effective than a single-stage one, if it is necessary to allocate no more than 64 narrowband channels.
- A. Palomo Navarro; Rudi Villing; Ronan Farrell. Efficient Channelization for PMR+4G and GSM Re-Farming Base Stations // IET Irish Signals and Systems Conference (ISSC 2012). 2012. P. 1−6.
- A. Palomo Navarro; Tony Keenan; Rudi Villing; Ronan Farrell. Non-uniform channelization methods for next generation SDR PMR base stations // IEEE Symposium on Computers and Communications (ISCC). 2011. P. 620−625.
- F.J. Harris. Multirate Signal Processing for Communication Systems. Prentice Hall PTR. 2004. 496 p.
- Fangzhou Wu; Rudi Villing. FPGA based FRM GDFT filter banks // 27th Irish Signals and Systems Conference (ISSC). 2016. P. 1−6.
- W.A. Abu-Al-Saud G., L. Stuber. Efficient wideband channelizer for software radio systems using modulated PR filterbanks // IEEE Transactions on Signal Processing. 2004. V. 52. № 10. P. 2807−2820.
- Bo Li; Jian Yan; Xiang Chen; Shunliang Mei. A high-resolution wideband digital channelizer for software radio systems using high-order perfect reconstruction filterbanks // IEEE Wireless Communications and Networking Conference (WCNC). 2013. P. 2908−2913.
- Parks, Thomas W., C. Sidney Burrus. Digital Filter Design. New York: John Wiley & Sons. 1987. P. 360.
- Mehmood Awan, Yannick Le Moullec, Peter Koch, Fred Harris. Polyphase Filter Banks for Embedded Sample Rate Changes in Digital Radio Front-Ends // Special Issue on advances in Digital Front-End and Software RF Processing: Part II, ZTE Communications. December 2011. V. 9. № 4. P. 3−9.
- Spazhakin M.I., Tokarev A.B. Sravnitel'ny'j analiz okonny'x funkczij, ispol'zuemy'x dlya razrabotki bankov czifrovy'x fil'trov mnogokanal'ny'x sistem radiomonitoringa // Cb. trudov XXIII Mezhdunar. NTK «Radiolokacziya, navigacziya, svyaz'». Voronezh: VGU. 2017.
- GOST R 53529-2009. Trankingovy'e radiostanczii i retranslyatory' standarta TETRA. Osnovny'e parametry'. Texnicheskie trebovaniya.
- Ashixmin A.V., Litvinov A.I., Pershin P.V., Polyakov A.V., Sergienko A.R., Spazhakin M.I., Tokarev A.B. Czifrovy'e radiopriemny'e ustrojstva texnicheskix sredstv radiomonitoringa // Specztexnika i svyaz'. 2016. № 4. S. 90−97.