The subject matter of the paper is the processes of analysis and evaluation of the effectiveness of information coding methods in wireless systems. The aim is to improve noise immunity of information messages under conditions of powerful electromagnetic interference, with the help of complex signal-code constructions. The objective is to develop a method for noise-immune encoding in a wireless information transmission system, providing increase in information transmission rate. The methods used: Simulation and digital signal coding. The following results have been obtained: A method for encoding information transmitted via wireless communication lines in presence of interference. For signal coding, it is proposed to use Gaussian monocycle with time-dependent position-pulse modulation (PPM). It is shown that for organization of independent channels within a single frequency band, it is practical to use a system of orthogonal codes. Pulses of the useful information signal accumulated in a receiver correlator provide significantly increase in signal-to-noise ratio, allowing transmission of information over a wide frequency range well below the noise level. As a result of encoding information in wireless information transmission systems with the help of ultra-short pulse signals, the effectiveness of the proposed method is a quantitatively and qualitatively evaluated. Conclusion. Using Pulse Position Modulation coding in wireless information transmission systems allows transmitting large volumes of information with high transmission rate and high noise immunity of the communication channel as well as protecting the channel from message interception. Ability to work with low radiating power and high signal capacity to penetrate various obstacles ensure fulfilment of electromagnetic compatibility requirements as well as stable communication in conditions of multipath radio wave propagation. A possibility that powerful electromagnetic disturbances accompanying a lightning discharge may have catastrophic impact on the information transmission channel is also eliminated. K e ywor d s : wireless communication line; information coding method; time-dependent position-pulse modulation; lightning discharge; electromagnetic compatibility; electromagnetic interference.

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The subject matter is analysis and evaluation of efficiency of noise-like signals in wireless information transmission systems. The aim is quality of service improvement for mobile subscribers, due to communication channel multiplexing using complex signal-code structures. The objective is development of a systemic view of the technology of information transmission using ultra-short pulse signals focusing on main phenomena that arise at different stages of signal transmission in a wireless information transmission system. The methods use dare sequential analysis, simulation modeling and digital signal coding. The following results have been obtained. An antenna design featuring an expanding slit has been proposed for effective emission and reception of noise-like signals. A method for controlling radiation pattern of such antenna array has been developed. Gaussian Monocycle coding of information with time position-pulse modulation has been justified to be used as a noise-like signal. It has been shown that for the organization of independent channels in one frequency band, it is practical to use a system of orthogonal codes, e.g. Walsh sequence. Due to accumulation of pulses of a useful information signal in the receiver correlator, significant increase in signal-to-noise ratio becomes possible, which enables information transmission over a wide frequency range well below the noise level. As a result, a systematic understanding of the technology of information transmission using ultra-short pulse signals in wireless information transmission systems is developed and a quantitative evaluation of the efficiency of the proposed technical solutions is provided. Conclusion. The use of noise-like signals in wireless information transmission systems provides for high data transmission rates with high interference immunity and tapping protection communication channel. The ability to operate with low emitted power and the high penetrability of noise-like signals through various obstacles, for example, walls, allow meeting the requirements for electromagnetic compatibility and ensuring stable communication in conditions of multipath propagation of radio waves. These circumstances form the basis for the development and implementation of information transfer technology using noise-like signals when designing office networks.K e ywor d s : noise-like signal; wireless information transmission system; time position-pulse modulation; orthogonal coding; electromagnetic compatibility.

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