SU1352662A1 - Device for retrieval by delay of combination pseudorandom sequences - Google Patents

Abstract

The invention relates to radio engineering and provides a reduction in the search time for the delay of the combined pseudo-random sequences (PSP). The device contains the block 1 of the initial installation, the correlator 2, the threshold block 3, the M-input element AND-NOT 4, the element OR 5, shapers 6.8 pulses, frequency dividers (QH) 7.9, delay elements 10, 11 , PSP generator 13, M-channel synchronism search unit 12, each channel of which consists of a correlator 14, threshold block 15 and prohibition block 16. Generator 13 consists of initial PSP generators 17, delay elements 18, And 19 elements, switching matrix 20 decoder 21, the elements of OR 22, the element OR 23, D of the trigger 24 and the generator 25 clock pulses. DF 7 sets the integration interval in the frequency synchronization paths. Initially, the initial bandwidth band 17 is synchronized with the generators. Then, the correct bandwidth input of the main band generator generators 17 is checked by determining the correlation function of the received combined bandwidth and reference combination bandwidth in the correlator 2. PM 9 sets the integration interval at this stage. When the value of the correlation function reaches a predetermined threshold, a signal appears at the end of the search for the combined SRP. 1 il. P 00 SP 1CHE O5 os 1L.

Description

The invention relates to radio engineering, mainly to the technique of pseudorandom signal detection in broadband communication systems, in which. combined pseudo-random sequences (PPS) are used.

The aim of the invention is to reduce the search time by the SSP delay.

The drawing shows a structural electrical circuit of the search device for delayed DSP.

The search device, but the MTP delay contains a setup block 1, an additional correlator 2, an additional threshold block 3, an M-input element AND-HE 4, an element OR 5, the first driver 6 impulses,

the first frequency divider 7, the second Vor-2o blunt on the clock input of the correlator

14. through the delay element 10. This allows to take into account the possible displacement of the fronts of the symbol bandwidth due to the inertia of the prohibition element 16. and ge14. through the delay element 10. This allows to take into account the possible offset of the front edges of the memory bandwidth due to the inertia of the inhibit element 16. and 8 helium impulses, the second frequency divider 9, the first and second delay elements 10 and 11, the M-channel synchronism search unit 12 and the generator 13 a pseudo-random sequence of the initial PSP generator 17. and exclude information (PSP), moreover, the correlators, threshold blocks 15, -15, prohibition blocks,

thirty

in the field of their fronts. The integration time in the correlator 14. is set and the generator 13 SRP includes the original SRP generators, delay elements, AND elements, switching matrix 20, decoder 21, OR elements 22-22, OR element.23, D-flip-flop 24 and generator 25 clock pulses (TI).

The search device for the delay KPSP works as follows.

The device returns to the initial state and the beginning of the search is carried out by the initial installation block 1, the pulse from whose output through the additional element OR 5 is fed to the additional installation inputs. the correlators of the M-channel. of the synchronization search block 12 and brings them to the initial state .j and also goes to the R-input of the first frequency divider 7, which determines the beginning of the integration interval in the private synchronization paths. At the same time, from the outputs of the threshold blocks, zero potentials arrive at the M-input element AND-HE 4, the unit potential from the output of which brings the additional correlator 2 to the initial state via the additional setting input and the second divider 9. the noR-input frequency and provides under 35

40

45

50

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the first divider 7 frequency generator 25 TI. From the output of this divider, through the first pulse shaper 6, the signal for the end of the integration time is fed to the control input of the i-ro threshold unit 15. If the correlation function has not reached the specified threshold by this time, then the second output of the threshold block 15 receives the input signal block prohibition 16, eliminating a single pulse from the clock sequence from the output of the generator 25 TI, coming through the block prohibition 16. to the clock input of the generator of the original SRP 17.. As a result, the generator sequence of the initial PRS 17 is delayed by one cycle with respect to the KPSP and the search process is repeated, which is ensured by setting the correlator 14 to the initial state by a signal from the first output of the threshold block 15, supplied to the installation input of this correlator 14,.

When the correlation function reaches a predetermined threshold and the pulse arrives at the end of the integration time from the first frequency divider 7, the signal from the third output of the threshold unit 15 blocks the redirecting of this state until all the generators of the initial memory bandwidth 17 17 | will not go into synchronism.

The introduction of these generators into synchronism is as follows.

At the first input, the i-ro correlator of the torus 14j is fed to the KSP, and to

the second input input is the source bandwidth from the output of the i-ro generator source bandwidth 17j. This device uses a correlator based on the modulo summation of two character KPSP and

PSP and counting the number of pulses of coincidence and mismatch of characters using a clocked reversible counter. In this case, the clock pulses from the second output of the generator 25 are fed to the clock input of the correlator

14. through the delay element 10. This allows us to take into account the possible displacement of the fronts of the PSP symbols due to the inertia of the prohibition element 16. and the original PSP generator

5 of the original PSP generator 17. and exclude the strobe of the characters KPSP and PSP

0

in the field of their fronts. The integration time in the correlator 14. is set to 5

0

five

0

five

the first divider 7 frequency generator 25 TI. From the output of this divider, through the first pulse shaper 6, the signal for the end of the integration time is fed to the control input of the i-ro threshold unit 15. If the correlation function has not reached the specified threshold by this time, then the second output of the threshold block 15 receives the input signal block prohibition 16, eliminating a single pulse from the clock sequence from the output of the generator 25 TI, coming through the block prohibition 16. to the clock input of the generator of the original SRP 17.. As a result, the generator sequence of the initial PRS 17 is delayed by one cycle with respect to the KPSP and the search process is repeated, which is ensured by setting the correlator 14 to the initial state by a signal from the first output of the threshold block 15, supplied to the installation input of this correlator 14,.

When the correlation function reaches a predetermined threshold and the pulse arrives at the end of the integration time from the first frequency divider 7, the signal from the third output of the threshold unit 15 blocks the 14 j correlator, and from the fourth output of this threshold unit 15. to the corresponding input of the M input element AND-NOT A signal is given for the end of synchronization of the generator of the initial bandwidth 17, -. When the inputs of the M-input element AND-NOT 4 signals from all the threshold blocks 15, -15, a signal is taken from its output, supporting in the initial state the additional correlator 2 and the second frequency divider 9. This starts the stage of checking the correctness of introducing into the synchronism of the initial PSP generators by determining in the additional correlator 2 the value of the correlation function of the received KPSP coming from the input of the device to the input of the additional correlator to-2 o vm pulse shaper, S after 2 and reference KTPS taken from the output D-flip-flop 24, which is the output of the SRP generator 13, and arriving at the second input of the additional correlator 2. The principle of correlation signal processing is discussed above, and the purpose of the second lementa delay 11 is the same as that of the first delay element 10 for paths private sync. The integration interval is set by the second frequency divider 9, and the signal for the end of the integration time from it through the second driver 8 pulses goes to the setup input of the additional correlator 2, returns it to the initial state, and to the control input of the additional threshold unit 3, If the value of the correlation function did not reach the threshold (which indicates incorrect synchronization of one or several generators of the initial SRP 17), then the signal from the output of the additional 30

formatively connected - the second frequency divider and the second pulse shaper, the initial setup block, the MAND input element, the first and

25, the second delay elements, the block is banned to each channel of the synchronism search block, while the information input of the additional correlator is connected to the information input of the synchronism search block, in each of the M channels of which the reset, lock, delay, and control outputs of the threshold block are respectively connected reset and blocking inputs of the correlator, block delay input. ban and with the corresponding input of the M-input element AND-NOT, the output of which is respectively connected to another input of the second divider and

40 by the gating input of the additional correlator, and the clock output of the pseudo-random sequence generator is connected to the corresponding inputs of the first and second dividers.

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threshold unit. 3, through the blocking element element 45 in the syncROLI search block 5, translates the private synchronization path and the first frequency divider 7 to the initial state and provides a repeated search cycle in the private synchronization paths. When the value of the correlation function reaches a predetermined threshold, at the second output of the additional threshold block 3, which is the output of the device, a signal appears to indicate that the end of the search of the CSP.

Claims (1)

Formula  Search device for delayed combined pseudo-random through the first delay element — with the corresponding inputs of the correlators in the synchronism search block, and through the second delay element — with 50 with the corresponding input of the additional correlator, and the output of each prohibition block is connected to the corresponding input of the pseudo-random sequence generator, the reference output of which is connected to the reference input of the additional correlator, the setup input of which is connected to the output of the second pulse generator and the setup input sequences, containing a search block, the composition of each of the M channels of which includes serially connected correlator and threshold block, where the information inputs of all correlators are connected and are the information input of the device, and the reference inputs are connected to The corresponding outputs of a pseudo-random sequence generator, characterized in that, in order to reduce the search time for the delay of the combined pseudo-random sequences, a successively connected additional correlator, an additional threshold unit, a P1PI element, the first frequency divider and the first formatively connected - the second frequency divider and the second pulse shaper, the initial setup block, the MAND input element, the first and 5 second delay elements, a block on each channel of the synchronism search block, while the information input of the additional correlator is connected to the information input of the synchronism search block, in each of the M channels of which the reset, block, delay and control outputs of the threshold block are respectively connected to the reset inputs and blocking the correlator torus, block delay input. ban and with the corresponding input of the M-input element AND-NOT, the output of which is respectively connected to another input of the second divider and 0 by the gating input of the additional correlator, and the clock output of the pseudo-random sequence generator is connected to the corresponding inputs of the first and second dividers. five through the first delay element — with the corresponding inputs of the correlators in the synchronism search block, and through the second delay element — with the corresponding input of the additional correlator, while the output of each prohibition block is connected to the corresponding input of the pseudo-random sequence generator, the reference output of which is connected to the reference input of the additional correlator, the installation input of which is connected to the output of the second pulse shaper and the installation input 51352662 threshold unit, another output which is connected to the installation inputs is the output of the device, the synchronism block correlators, in and the installation input of the device in which the control inputs are thresholds Is the input block of the initial set-block connected to the output of the second ki, whose output is connected to another pulse generator, the input of the element OR, the output of which