SU684755A1 - Device for synchronization of complex multifrequency signals - Google Patents

Description

I

The invention relates to communications and can be used in radio receiving devices of broadband information transmission systems.

A device for synchronizing complex multi-frequency signals is known, which contains a series-connected multiplier, a filter, a detector, and a decisive unit, as well as a reference signal generator, the output of which is connected to another input of the multiplier 1.

However, this device has a significant time searching for synchronism.

The aim of the invention is to reduce the search time synchronism.

For this, the device synchronizes complex multi-frequency signals containing a series-connected multiplier, filter, detector, and solver unit, as well. also the reference signal generator, the output of which is connected to another multiplier input, is a series-connected additional filter, an amplitude detector, an integrator, an additional decision block and a coarse search, as well as a series-connected key and an exact search block,

the output of the multiplier is connected to the input of the additional filter, the output of the additional decision block and the output of the decision block are connected to the corresponding key inputs, and the output of the exact search block is connected to the input of the reference signal generator via the coarse search block.

The drawing shows a structural electrical circuit of the proposed device.

The device for synchronizing complex multi-frequency signals contains multiplier 1, filter 2, detector 3, decision block 4, key 5, reference signal generator 6, additional filter 7, amplitude detector 8, integrator 9, additional decision block 10, search unit 11. search unit, block 12 coarse search.

The device works as follows.

A complex multi-frequency cigaal, which is a set of N complex signals having a duration T and a spectral width Fg, which are emitted sequentially in time at different carrier frequencies spread across the FQ interval, according to

with a code defining the order of the frequency sequence, is fed to the input of multiplier 1, to the other input of which the reference layer multi-frequency signal is fed from the output of generator 6.

The signal search is carried out in two stages. At the first stage, the signal parameters (delay and frequency) are roughly determined. This operation is performed by an additional filter 7, an amplitude detector 8, an integrator 9, an additional decision block 10 and a block 12. In the absence of a signal, block 12 changes the delay and frequency of the reference signal with a resolution of 1 / IDA 1 / Td, providing a transition from analyzing one element to the analysis of the next element. At the same time, key 5 is open, and block 11 does not affect operation. Upon detection of a signal, block 12 stops rebuilding, closes key 5, which connects decisive block 4 to block 11. The signal coming from the output of multiplier 1 is accumulated by filter 2, the result of the accumulation is detected by detector 3, decisive block 4, the decision} in the analysis element. In the absence of a signal, block 11 changes the delay and frequency: of the reference signal of generator 6, to ensure that the next element is analyzed. The delay and frequency tuning in this case is carried out with a discretization of 1 / F and 1 / T, where F d N and T. TdM In the presence of a signal at the output of the decision block 4, the block 11 stops the restructuring of the reference signal of the generator 6.

The coherent device allows the e1 to significantly decrease the average signal search time and is distinguished by its simplicity in technical implementation.

Claims (1)

1. Pestr VB et al. Noise-like signals in information transmission systems, M., Sov. radio, 1973, p. 167.