ANALYTICAL MODEL OF NOISE IMMUNITY ESTIMATION OF FAST DELAY ACQUISITION PROCEDURES BASED ON FAST TRANSFORMATIONS

Object of consideration - asynchronous-address, command-measuring systems, using code division of channels. The subject of the analysis is the delay acquisition devices for long sequences. The purpose of this study is to develop models to assess the efficiency of two-stage delay acquisition devices based on the fast transformations. The principles of two-stage processing and fast transformations provides a wide variety of delay acquisition schemes. Developers are keen to provide a compromise between speed and complexity of devices. The problem of a device implementation variants justified choice is the accuracy of the energy efficiency estimate. The paper proposed analytical model to estimate the delay acquisition device implementation efficiency indicators based on the fast transformations. Key features of the model are the possibility of obtaining accurate assessment of delay acquisition device implementation variants based on the fast transformations in the Galois Fields. The exact dependences of the main efficiency indexes of two-stage search schemes on thresholds in the decision blocks are found. The digital nature of signal processing prevents the use of approximate estimates based on analog models due to their inadequacy. In order to correctly compare the proposed device with the optimal variant, the Gaussian channel is mapped to a binary symmetric channel (BSC) with an equivalent error probability value per symbol. A computational model of error probabilities for each digital block of delay acquisition devices is developed. It provides an estimate of the gain in time and accuracy of the search under various decision criteria and thresholds in a two-stage schemes. The results will be useful for professionals involved in the design of complex signals and their processing devices to ensure safety and protection against interference.