Construction of multifunctional radio monitoring systems based on a family of small-sized digital radio receivers and modules.

Construction of multifunctional radio monitoring systems based on a family of small-sized digital radio receivers and modules..

REMBOVSKY Anatoly Markovich, Doctor of Technical Sciences, Senior Researcher
ASHIKHMIN Alexander Vladimirovich, Candidate of Technical Sciences
SERGIENKO Alexander Rostislavovich

CONSTRUCTION OF MULTIFUNCTIONAL RADIO MONITORING SYSTEMS BASED ON A FAMILY OF SMALL-SIZED DIGITAL RADIO RECEIVING DEVICES AND MODULES  

The domestic market of technical means of radio monitoring has undergone significant changes over the past 5-6 years. Several generations of radio monitoring, direction finding, and detection of technical channels of information leakage complexes based on domestic digital radio receivers (DRR) have been developed and launched into serial production. This article continues [1-2] a series of works devoted to new developments based on modules of the ARGAMAK series, and develops an approach to the construction of multifunctional technical means, which is comparatively little covered in domestic periodicals, consisting in combining several DRR to solve such problems as increasing the productivity of panoramic analysis, ensuring coherent multichannel processing, multichannel radio monitoring and recording of radio signals in vector form in mass service systems, etc. Such an approach, combined with the use of additional equipment and software packages, as will be shown below, allows for the solution of most automated radio monitoring problems while minimizing costs.

The most important technical characteristics, performance, and functionality of the radio monitoring complex directly depend on the radio receiver used as the core of the complex. For a long time, domestic manufacturers were forced to use imported communication receivers, abundantly presented on the Russian market, complete with

FFT processors. The undoubted advantage of this approach is its comparative cheapness. However, this approach has a number of significant disadvantages, including limited functionality, performance, and a number of other technical characteristics. In the end, the communication receiver is not required to provide high performance when used for spectral analysis.

The situation changed radically after about six years ago, when domestic digital panoramic RPU ARK-CT based on single-channel (ARK-CT1) and dual-channel (ARK-CT2) radio signal converters were developed and launched into serial production. In the multifunctional portable radio monitoring and detection complex of technical information leakage channels created on the basis of ARK-CT1

ARK-D1T achieved high performance indicators for the Russian market at that time of 150 MHz/s and a dynamic range for third-order intermodulation of 70 dB. This TsRPU replaced imported communication receivers also in mobile and stationary radio monitoring and direction finding systems. On its basis, the measuring devices ARK-D1TI and ARK-D1TR [3 – 5], certified by the State Standard of the Russian Federation, were created.

The next stage was the creation of a two-channel 4th generation TsRPU based on ARK-TsT3 radio signal converters. This device allows coherent parallel reception on two channels and has a dynamic range of

70 dB for each channel, a simultaneous analysis band of 5 MHz. The device served as the basis for the creation of a two-channel complex for radio monitoring, direction finding and detection of technical channels of information leakage ARK-D7K, providing a panoramic analysis speed of up to 2000 MHz/s in the entire operating range. This product also became the basis for the construction of a series of mobile and stationary multifunctional complexes for radio monitoring and direction finding of the 4th generation, implementing a two-channel modification of the correlation-interferometric direction finding method [6].

Despite the undoubted advantages, including high technical characteristics, productivity, functionality, the specified radio receivers also had disadvantages — relatively large dimensions, heavy weight and increased energy consumption. Another disadvantage of the III and IV generation radio receivers is the relatively low technological efficiency of their production. In this regard, the task arose of developing a new generation radio receiver, which, having all the positive characteristics of its predecessors, at the same time would have low weight and size indicators and would be more technologically advanced in production.

ARGAMAK Family Modules

At the end of last year, a new 5th generation of radio receivers and their modules of the ARGAMAK series was developed [1, 7]. The ARGAMAK digital radio receiver in its basic composition includes two main modules: the ARK-PS5 radio signal converter (when placed in a case, it has the ARGAMAK-T code), which transfers radio signals to one of the intermediate frequencies, and a digital processing module, which performs analog-to-digital processing of the signal at the intermediate frequency. ARGAMAK-T makes it possible to receive a radio signal at the intermediate frequency, but to solve the main problems of radio monitoring, this signal must be converted into digital form and processed using specific algorithms. At present, there are two modifications of the digital processing module ARK-TsO2 and ARK-TsO5, which perform digital signal processing in the 2 MHz and 5 MHz bands with a resolution of 3 and 6 kHz, respectively. A module ARK-TsO10 with a simultaneous processing band of 10 MHz has also been developed. In addition, the modules include a specialized ARC-C5 calculator, which, in combination with the ARC-CO modules, allows for a significant increase in digital processing performance. The functional diagrams of the ARC-CO10 and ARC-C5 are shown in Figs. 1, 2, and the technical characteristics are in Tables 1 – 3.

Table 1. Technical characteristics of the ARC-CO10 module

Fig. 1. Functional diagram of ARC-CO10

Fig. 2. Functional diagram of the ARC-C5

Table 2. Technical characteristics of the ARC-C5 module

Table 3. Variants of ARK-TsO5, ARK-TsO2, ARK-TsO10

To date, the ARGAMAK series modules have been used to create the ARGAMAK-I panoramic measuring receiver [5], the ARK-NK3I portable measuring complex for radio monitoring and direction finding based on it, the ARK-RP3 hand-held direction finder, and the ARK-RP4 hand-held direction finder of broadband signals [1].

Increasing processing performance (panoramic analysis speed)

To improve the processing performance in a wide frequency range, two main approaches can be used. The first of them is to expand the band of simultaneously processed frequencies with a corresponding increase in the ADC bit depth and an increase in the processing processor power. This approach is certainly justified with low electromagnetic environment (EME) load or processing of broadband signals from a single source, all spectral components of which are related to each other by certain amplitude ratios.

In case of using panoramic analysis technical means for EMI assessment in urban conditions, when a large number of independent narrow-band radio emission sources (RIS) are operating, the presence of at least one powerful RI in the simultaneous analysis band leads to overload and errors in assessing the level of the remaining RIS in the same analysis band. Therefore, in these conditions, another approach is justified, implemented in the construction of the below-mentioned means, the essence of which lies in the combination of a certain number of physical frequency selection channels (ARC-PS5 radio signal converter modules) and digital processing modules (ARC-CO).

The proposed multichannel panoramic radio receivers ARK-RD8M can have several (from 2 to 8) independent radio signal converters ARK-PS5 controlled from one PC and, accordingly, from 1 to 4 two-channel digital processing modules ARK-TsO with simultaneous analysis bands of 2, 5 or 10 MHz in each channel. In addition, to implement the maximum speed of panoramic analysis, these devices include high-performance two-channel specialized calculators ARK-S5, reducing the FFT calculation time to 100 μs.

The functional diagram of the ARK-RD8M/4 product with four physical channels of frequency selection from 25 to 3000 MHz each is shown in Fig. 3.

 
Photo 1. External appearance of the ARK-RD8M/4 product

Fig. 3. Functional diagram of the ARK-RD8M/4

The obtained characteristics of the multichannel panoramic receiver ARK-RD8M/4 are given in Table 4.

Operating frequency range:
    — basic configuration 25-3000 MHz
    — maximum configuration 9 kHz…18 GHz
Attenuator 0…30 dB in 2 dB steps
Sensitivity 1.5 μV
Dynamic range for 3rd and 2nd order intermodulation 75 dB
Intermediate frequency interference attenuation, not less than 70 dB
Selectivity for the mirror channel, not less than 70 dB
Bandwidth of simultaneous spectral analysis in each channel
    — for ARK-CO55 MHz
    — for ARK-CO1010 MHz
Speed ​​in the operating range for 2…8 channels
    — for ARK-CO5 (resolution 6 kHz) 8…32 GHz/s
    — for ARK-TsO10 (resolution 12 kHz) 16…64 GHz/s
Power supply:
    — from AC network 90 – 250 V
    — from the vehicle's on-board network 10.6…13.6 V
    — from an autonomous battery 12 V

Number of monitored channels 2 8
Number of frequencies in the scanning task 255
Number of ranges in the search task 255
Resolution of tuning to a radio signal 1 Hz
Types of demodulation AM, FM, OBPv, OBPn, telegraph transmissions

Recording of radio signals, technical analysis:

Processed frequency band/resolution
    — for ARK-TsO5 5 MHz/15 kHz, 250 kHz/500 Hz, 120 kHz/240 Hz, 50 kHz/100 Hz, 25 kHz/50 Hz, 9 kHz/20 Hz, 6 kHz/12 Hz
    — for ARK-TSO10 10 MHz/30 kHz, 250 kHz/500 Hz, 120 kHz/240 Hz, 50 kHz/100 Hz, 25 kHz/50 Hz, 9 kHz/20 Hz, 6 kHz/12 Hz

When tagging
The parameters of each receiving path are determined by the characteristics of the ARGAMAK central receiver unit.

The number of physical channels of the ARK-RD8M product, depending on the tasks being solved, can vary from two to eight, while the range of possible PA speeds for different modules is determined by Table 5.

Table 5

The receiver is controlled using an external PC. The following special software packages are provided for working with the receiver:

• SMO-PA8M – software package for panoramic analysis;
• SMO-RD8 – software package for multichannel radio monitoring;
• SMO-TA2 is a software package for technical analysis.

Under the control of these packages, the receiver provides the following functions [1]:

• panoramic spectral analysis of radio signals with parallel restructuring of radio signal converters connected to one antenna;
• panoramic spectral analysis of radio signals with a separate independent task for each channel;
• accumulation of a panorama of spectra in a given frequency range, saving a panorama of the range loading for subsequent analysis;
• statistical analysis of panoramic analysis results;
• pairwise coherent multichannel signal processing for use in various applications;
• search for active radio channels in a frequency range or by frequency list, automatic registration of found radio emission sources;
• recording of radio signals by IF in vector form on a PC hard drive;
• technical analysis, determination of modulation type and measurement of radio signal parameters;
• recording demodulated transmissions on a PC hard drive;
• playback of demodulated signals recorded on a PC hard drive;
• listening to demodulated signals in real time;
• generation of reports with the results of radio monitoring and signal analysis.

It should be noted that when operating in the panoramic spectral analysis mode with all channels connected to one antenna, it is possible to achieve a total throughput of 64 GHz/s with a resolution of 12.5 kHz.

Ensuring coherent multichannel processing

Special attention during the design and development of the ARC-PS5 radio signal converter was given to the possibility of ensuring coherent operation of several devices, for example, for use in monopulse direction finding systems. For this purpose,

The ARC-PS5 provides the ability to both output signals from internal heterodynes of the receiver to the synchronization connectors and receive signals from an external source from the same connectors with their subsequent use as heterodynes. Switching the purpose of the synchronization connectors (input/output) is carried out programmatically. Synchronization of the reference frequency generators is organized in a similar way. Thus, the following operating modes of the ARC-PS5 can be organized as part of the complex:

• fully autonomous operation of the ARC-PS5 converter from the internal reference generator;
• autonomous operation from an external reference generator in order to increase the stability and accuracy of frequency setting, as well as the possibility of frequency synchronization of a complex of several ARC-PS5 converters;
• operation of internal heterodynes from an internal or external reference generator with the output of heterodyne signals to synchronization connectors to ensure paired coherent operation of ARC-PS5 converters (for example, as part of direction finding systems);
• operation with the internal reference generator and heterodynes switched off to ensure coherent operation of several ARK-PS5 products (as part of direction finding systems).

The ARK-PS5 radio signal converter is controlled via a serial port with the RS485 physical protocol. This choice is due to the need to ensure control at a distance of up to several hundred meters, for example, when building distributed remote radio monitoring systems ARK-D13 with functions similar to the ARK-D3T, ARK-D9 [8] complexes.

Multi-channel radio monitoring

This section describes the ways of implementing multi-channel radio monitoring, which became possible due to the features of the proposed ARK-CO module.

The selected internal architecture of the digital processing module ARC-CO makes the following capabilities available. It provides for the presence of analog filters that allow for an unambiguous representation of the signal in digital form. Demodulation of the signal for auditory control is carried out by software and hardware, which allows for an increase in the number of permissible types of modulation without changing the hardware and reducing the mass and dimensions of the module. It is possible to register signals in vector form for subsequent technical analysis. The module provides simultaneous operation in panoramic analysis and signal demodulation mode. The module is dual-channel (table 3), which allows, when using a two-channel analog radio signal converter, to perform coherent processing of signals received on both channels. The module ensures high performance in solving problems of direction finding, demodulation and recording of radio signals in vector form. The module is a link in the control system of the radio monitoring complex, providing exchange between a PC or other control device, digital signal processors, radio signal converters and additional equipment.

The functional diagram of the ARC-RD8/8 product with eight physical channels of frequency selection from 25 to 3000 MHz contains eight ARC-PS5 radio signal converters and four two-channel digital processing modules ARC-TsO2.10 (Table 3). Its structural diagram differs from the one shown in Fig. 3 of the ARC-RD8M/4 by the absence of specialized ARC-S5 calculators and by the fact that the ARC-TsO2 modules with a simultaneous analysis band of 2 MHz are used as basic ones.

Along with the radio monitoring functions, the ARK-RD8 product provides the ability to solve problems of identifying technical channels of information leakage and special studies for the presence of PEMIN. It provides the ability to generate specialized test sound signals used in special studies of premises.

The characteristics of the multichannel panoramic receiver ARK-RD8 basically coincide with the characteristics of the ARK-RD8M/4, given in Table 4. There are differences in the values ​​of the simultaneous analysis bands, resolution and speed of spectral analysis in the operating range. These parameters for ARC-RD8 are presented in Table 6.

Panoramic analysis, fast signal search

Band of simultaneous spectral analysis in each channel 2 MHz
Speed ​​in the operating range for 2…8 channels 1.2…4.8 GHz/s

Recording of radio signals, technical analysis

Bandwidth of processed frequencies/resolution
    — forARC-CO2: 2 MHz/7 kHz, 250 kHz/500 Hz, 120 kHz/240 Hz, 50 kHz/100 Hz, 25 kHz/50 Hz, 9 kHz/20 Hz, 6 kHz/12 Hz

A simplified version of a multi-channel panoramic receiver

The above-considered properties of the ARK-PS5 radio signal conversion module and the ARK-TsO digital processing modules allow the design of systems for a wide range of purposes, including multi-channel radio monitoring systems, multi-channel remote radio monitoring systems in one or more rooms, monopulse direction finders, and measuring equipment. Of particular interest is the two-channel modification of the ARK-D11 product ARK-RD8M, which is essentially a further development of the ARK-D7K equipment based on modules from the ARGAMAK family.

Currently, the development of the two-channel multifunctional radio monitoring and information leakage channel detection complex ARK-D11 based on the ARGAMAK series modules has been completed.

The ARK-D11 complex is designed to solve radio monitoring problems and detect information leakage channels. In its functions, it is similar to the ARK-D7K complex [9, 10]:

• two-channel synchronous radio monitoring in real time with two coherently connected receiving and processing channels;
• two-channel radio monitoring;
• two-channel synchronous or single-channel search and detection of technical information leakage channels, accumulation and maintenance of a database on sources and processing of results;
• correlation reception of noise-like signals;
• recording of radio signals in vector form on a PC hard disk;
• technical analysis, determination of the type of modulation and measurement of radio signal parameters;
• monitoring of wired networks.

The ARK-D11 complex can also be used to solve direction finding tasks in combination with an additional direction finding antenna system and remote radio monitoring of several rooms (up to 11) as part of the ARK-D9 remote radio monitoring system [8].

Photo 2. ARK-D11 central unit

A distinctive feature of the basic model of the ARC-D11 complex is its internal architecture, namely, that it includes two ARC-PS5 radio signal converters, the outputs of which are connected to the inputs of the two-channel digital processing module ARC-TsO5 with a simultaneous analysis band of 5 MHz for each channel. Due to this, the complex has achieved the characteristics listed in Table 7. 

Table 7. Main technical characteristics of the ARC-D11

Operating frequency range in the basic configuration 9 kHz – 3000 MHz
Frequency range in the maximum configuration 9 kHz – 18 GHz
Input attenuator, dB 0 – 30 dB in 2 dB steps
Maximum allowable input voltage 23 dBm
Noise figure
    — in the range of 25 – 465 MHz no more than 12 dB
    — in the range of 465 – 3000 MHz 12 – 14 dB

Relative error of tuning frequency ±5х10-7
Temperature instability in the range of -20… +50° C±5х10-7
Frequency instability per day ±5х10-7

Selectivity and nonlinear distortion:

Intermediate frequency interference attenuation, not less than 70 dB
Image channel selectivity 70 dB
Dynamic range for 3rd and 2nd order intermodulation 75 dB
Third order intermodulation intersection point (IP3) at the input, not less than
    — without attenuators 0 dBm
    — with the attenuator on 30 dB30 dBm
Unevenness of the transmission coefficient in the operating frequency range of the basic version, no more than ±3 dB

Analog signal frequency IF 10.7 MHz, 41.6 MHz,
Bandwidth to IF output 10.7 MHz with unevenness of ±1 dB 2 MHz
Bandwidth to IF output 41.6 MHz with unevenness of ±1.5 dB 5 MHz
Receiver sensitivity in AM and FM modes, no worse than 0.5 μV

Speed ​​of panoramic spectral analysis using:
    — ARC-CO2 module with a bandwidth of 2 MHz at an FFT resolution of 3 kHz1200 MHz/s
    — ARC-CO5 module with a bandwidth of 5 MHz at an FFT resolution of 6 kHz3000 MHz/s
    — ARC-CO10 module with a bandwidth of 10 MHz at an FFT resolution of 12 kHz6000 MHz/s
Input sensitivity 1 μV

Detection of technical information leakage channels (25 – 3000 MHz):

Crosstalk attenuation of antenna switches between channels, not less than 40 dB
Integral sensitivity of the system (transmitter power in a room with an area of ​​8?8 m2, detected with a probability of 0.99) 100 μW

The complex determines the location of radio microphones with AM, narrowband and wideband FM, static technical closure (without changing the closure parameters over time) indoors.

Control of wired networks(in the range of 0.05 kHz — 30 MHz):

Level of detected signals:
    — in the range of 0.05 kHz — 10 kHz less than 1 mV;
    — in the range of 10 kHz — 1 MHz less than 100 μV;
    — in the range of 1 MHz — 30 MHz less than 10 μV
Input resistance of the remote sensor of wired networks, not less than 1000 kOhm;
Voltage of wired networks up to 400 V

Bandwidth of processed frequencies/resolution 5 MHz/15 kHz, 250 kHz/500 Hz, 120 kHz/240 Hz, 50 kHz/100 Hz, 25 kHz/50 Hz, 9 kHz/20 Hz, 6 kHz/12 Hz

Number of frequencies in the scanning task 255
Number of ranges in the search task 255
Bandwidth of demodulators 250 kHz, 120 kHz, 50 kHz, 25 kHz, 9 kHz/, 6 kHz, 3 kHz
Resolution of tuning to a radio signal 1 Hz
Types of demodulation AM, FM, OBPv, OBPn, continuous radiation, telegraph transmissions

Operating temperature, weight, dimensions, power consumption:

Operating temperature range: -20… +50° C
Power supply:
    — from an AC network of 90 – 250 V
    — from an automobile on-board network of 10.6…13.6 V
    — from an autonomous battery 9…16 V
Power consumption, no more than 20 VA
Dimensions, 486x398x194 mm
Weight of the basic set 11 kg

The parameters of each receiving path are determined by the characteristics of the ARGAMAK CRPU.

Thus, the ARK-D11 product, having the main technical indicators better than those of the ARK-D7K, provides one and a half times greater productivity with significantly lower weight and energy consumption.

The products considered above are examples of the construction of ready-made systems based on the ARGAMAK series module family. An important circumstance, however, is that the modules are supplied by themselves, complete with the necessary documentation concerning the architecture and command system. Thus, interested organizations can use these modules to build systems of their own design, serving to meet specific requirements.

Comprehensive solution to radio monitoring problems with a limited set of tools

The hierarchical structure of automated radio monitoring (ARM) tools, their composition, functions, basic tactical and technical requirements for solving ARM problems in cities, industrial centers and on the ground, identifying technical channels of information leakage in one and many controlled zones and at their borders, as well as monitoring the effectiveness of measures to prevent information leakage at protected facilities have been substantiated earlier [11]. An attempt to implement such a structure in full for a specific user is associated with certain financial difficulties. The way out of this situation lies in the use of multifunctional tools that ensure the implementation of most ARM tasks with high efficiency while minimizing costs. In [9, 10] and this article, an approach to solving this problem is presented based on the use of one multichannel (in a minimum configuration, two-channel) panoramic receiving device of high performance. With this approach, the expansion of the number of functions is achieved by using additional software packages and additional equipment with a significantly lower (in comparison with the main core) cost.

In Table 8 an assessment of the possibility of performing various functions based on these complexes is given, the composition of additional technical means is presented and approximate data on the increase in cost for their implementation are given.

Table 8

Conclusion

The recently developed and serially produced family of modules of digital panoramic radio receivers of the ARGAMAK series, individual devices and complexes based on them open a new stage in the development of domestic radio monitoring equipment. As the core of radio monitoring systems, direction finding and detection of technical channels of information leakage, these products allow to significantly increase productivity while reducing weight and dimensions and maintaining other characteristics, to expand the number of functions available to the user without changing the hardware.

Examples of such systems are the panoramic multi-channel receiver ARK-RD8M, the multi-channel radio monitoring complex ARK-RD8 and the two-channel radio monitoring and information leakage channel detection complex ARK-D11.

The user can also design their own systems using the specified modules, which can be supplied separately complete with documentation on the internal architecture and command system. The possibilities for using the modules are limited only by the developer's imagination!

1. Rembovsky A.M., Ashikhmin A.V., Sergienko A.R., Portable means of automated radio monitoring. /Special equipment, 2004, No. 4

2. Ashikhmin A.V., Kozmin V.A., Rembovsky Yu.A. Portable system of radio monitoring and determination of location of radio emission sources. /Special equipment, 2005, No. 2,3.

3. ARK-D1TI – Multifunctional portable radio monitoring complex. Certificate of the State Standard of the Russian Federation on approval of the type of measuring instruments RU.C.35.002.A No. 13618 dated 03.12.2002, registered in the State Register of Measuring Instruments under No. 23924-02

4. ARK-D1TI – Multifunctional portable radio monitoring and detection of technical channels of information leakage. FSTEC Certificate No. 506/1 dated 01.02.2005.

5. ARK-D1TR – panoramic measuring receiver. Certificate of the State Standard of the Russian Federation on approval of the type of measuring instruments RU.C.35.002.A No. 13618 dated 03.12.2002, registered in the State Register of Measuring Instruments under No. 23924-02

6. Ashikhmin A.V., Vinogradov A.D., Kondrashchenko V.N., Rembovsky A.M., Modern correlation-interference instruments for measuring the bearing and electromagnetic field strength./Special equipment, Special issue, 2002, pp.30-42.

7. Panoramic measuring receiver ARGAMAK-I Certificate of the State Standard of Russia on approval of the type of measuring instruments RU.E.35.018.A No. 18189 dated 04.07.2004.

8. Ashikhmin A.V., Rembovsky A.M. Remote radio monitoring of premises: methods and means/Special equipment, Special issue, 2003.

9. Rembovsky A. M. Increasing the efficiency of automated radio monitoring search tools/Special equipment, 2003, No. 4.

10. Rembovsky A. M., Complex solution to radio monitoring problems based on multifunctional equipment with two reception-analysis paths/Special equipment, 2003, – No. 5.

11. Rembovsky A. M. Automated radio monitoring and direction finding of radiation – tasks and tools/Successes of modern radio electronics, 2003, No. 6.