JPS63278434A - Adaptive antenna system for fh communication - Google Patents

Abstract

PURPOSE:To quicken the FH by restricting the adaptive control at FH synchronization and setting the initial value of the adaptive control to a required value. CONSTITUTION:A signal outputted from an adder 6 is demodulated by a detection circuit 11 and noise is eliminated by a base band filter 12 and the output of the base band filter 12 is detected as to whether it is in the synchronizing state or not at that time by a synchronizing detection circuit 13 and the condition of a control condition set switch 17 is set. A weight control circuit 10 designates the restriction of the adaptive control in the synchronization acquisition state and the execution of control in the synchronizing state depending on the setting condition of the control condition setting switch 17. Moreover, an initial condition storage circuit 18, based on the hopping timing from a frequency synthesis section 16, stores the weight control converging data at the preceding hopping and gives it to the weight control circuit 10 as the weight initial data for the adaptive control at the next hopping. Thus, the adaptive control converging time is quickened.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to an adaptive antenna system for FH communication. [Prior Art] Figure @3 is a block configuration diagram showing a conventional adaptive antenna system for FH communication. In fig. (11 is the antenna, (2) is the mixer, (3) is the intermediate frequency filter, (4) is the A/D converter, (5) is the complex multiplication circuit, (6) is the adder, (7) is the received signal Output terminal, (8
) is the reference signal input terminal, (9) is the error detection circuit, α0 is the load control circuit, (b) is the detection circuit, CLl is the baseband filter, a3 is the synchronization detection circuit, (b) is the homping synchronization search circuit. ) is a clock input terminal, and αQ is a frequency synthesizer. In addition, the antenna (1) consists of N element antennas with a, b songs...n, and a mixer (2), an intermediate frequency filter (3), and a complex multiplier circuit (5) are also provided for each element. It is being Next, the operation will be explained. The received signal input from each element of the antenna (1) consisting of N elements is sent to the mixer (2).
The frequency of the signal is converted into an intermediate frequency signal by mixing it with the local oscillator signal generated by the frequency synthesizer u6. After unnecessary components are removed from the intermediate frequency signals by an intermediate frequency filter (3), each signal is converted into a digital signal by an A/D converter (4). The phase and level of each digitally converted element signal are weight-controlled by signals from a complex multiplication circuit (5) I and a weight control circuit αQ, which will be described later. Each load-controlled two-voltage signal is processed by an adder (
6) and output from the received signal output terminal (7). At this time. An error detection circuit (9) generates an error signal between the output of the adder (6) and the reference signal input from the reference signal input terminal (8), and forms a feedback loop to the load control circuit αQ.
The load control circuit α0 is controlled so that the error between the output of the adder (6) and the reference signal is minimized, and the complex multiplication circuit (5)
By adjusting the control amount, it is possible to achieve the effect of forming a minimum gain point in the interference direction without reducing the directional gain of the desired signal, which is a function of the adaptive antenna. On the other hand, as a synchronization method for FH codes, a method is generally used in which a preamble code for hopping code synchronization is added before data transmission, and the explanatory diagram is also based on this method. In this synchronization method, the signal output from the adder (6) is demodulated by a detection circuit (b). Noise components are removed with a baseband filter @. The output of the baseband filter @ is the synchronization detection circuit (to)
At that point, it is detected whether the synchronization state is present or not, and it is determined whether to continue or stop the synchronization search of the hopping synchronization search circuit αhiro. That is, if the synchronization state is not established, the sequential search is continued at the timing of the clock sent from the lock input terminal, and when the synchronization state is reached, the sequential search is stopped. In this way, the homping codes (preamble codes) are synchronized, and the frequency synthesizer α starts official hopping in the predetermined code order using the homping start position information specified from this synchronization timing as a trigger. [Problems that the invention seeks to solve] Since the conventional 7-dag tape antenna system is configured as described above, the adaptive antenna must start from a state where the direction of minimum gain is in the direction of the desired signal at the time of synchronization acquisition. Therefore, the reception sensitivity has to start from an extremely low state, making it difficult to realize a wide dynamic range antenna system that can be used in actual operation. This invention was made in order to solve the above-mentioned problems, and it is possible to create a wide dynamic range with strong anti-jamming properties without making almost any changes to the circuit configurations of the conventional FH communication device and adaptive antenna. It is an object of the present invention to obtain an adaptive antenna system for FH communication and also to obtain a device capable of realizing high-speed adaptive control and therefore high-speed FH. In the adaptive antenna method, the adaptive control is restrained so that it does not affect the reception sensitivity at the time of FH synchronization acquisition, and if the reception sensitivity at the time of synchronization acquisition is excluded from the influence of Sometimes, previous data in the convergence state is used as the initial value. [Operation] The adaptive antenna system for FH communication, which is the most advanced invention, performs adaptive control based on hopping synchronization and asynchronous information. By introducing control constraints that are open in the initial state and predicted set values for control initial values, the adaptive convergence time after synchronization is established can be shortened. explain about.@
2 in figure 1

[1] to α· are the same as those in the conventional example described above. αη is a control condition setting switch that selects control conditions for the adaptive antenna based on synchronization detection information from the synchronization detection circuit (to), and decoy is an initial condition memory for storing previous data as initial data for adaptive control after hopping convergence. It is a circuit. I will explain the operation shortly. The basic configuration of a receiver is l! This is the same as the case in FIG. 3, but the circuit configuration for controlling the load control circuit αq is different. The signal output from the adder (6) is demodulated by a detection circuit αη, and then noise is removed by a baseband filter. The output of the baseband filter (6) is sent to a synchronization detection circuit (to), which detects whether or not it is in a synchronized state at that time. Based on this signal, the load control circuit αQ specifies the constraint of adaptive control in the synchronization acquisition state and the control execution in the synchronization state by setting the conditions at the control condition setting switch a. Also, on the initial condition storage circuit side, based on the homp timing from the 1-frequency synthesizer αQ. The load control convergence data from the previous hopping is stored and held, and is supplied to the load control circuit aO as load initial data for the adaptive control during the first hopping. In the above embodiment, the load control circuit is controlled by the control condition setting switch αη and the initial condition storage circuit, but these functions may be realized by a software. In addition, regarding the homping synchronization acquisition state number, in the above embodiment, the base ζ was explained when performing a sequential search (sliding) using a preamplifier code, but other methods 1, for example, using a code correlator A similar effect is achieved even when the synchronization acquisition state is stuck. Figure 1g2 is a block diagram showing another embodiment of the present invention using this code correlator. ~ times are the same as the example of the St diagram. α9 is a code correlator such as a SAW convolver. SAW
When a co/volver is used, the code correlator 4 creates a correspondence between III and IQI using the structure of the SAW electrodes, and the arrangement of this structure constitutes the code of the homping pattern. Therefore, the received data that has passed through the detection circuit (b) and baseband filter (6) is compared and verified by the code correlator (SAW convolver), and when the codes completely match, the code correlation value becomes maximum and the synchronization timing is reached. will be output. Therefore. By controlling the frequency synthesizer αQ and the control condition setting switch ση using this synchronization information, the same effect as in FIG. 1 can be obtained. In this case, the code correlator α9 simultaneously achieves the same effect as the hopping synchronized search, so the hopping same M search circuit α used in the example of the 1gt diagram is unnecessary.
Also, the clock input (g) for search control becomes unnecessary. [Effects of the Invention] As described above, according to the present invention, since the adaptive control is constrained in the hopping synchronization acquisition stage, stable operation can be obtained, and the adaptive control initial stage after synchronization acquisition is Since the data before the load condition and homping are used, the adaptive control convergence time has the effect of speeding up.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing one embodiment of the invention, and FIG. 2 is a block diagram showing another embodiment of the invention. FIG. 3 is a block diagram showing a conventional adaptive antenna system for FH communication. In the figure, (1) is the antenna, (2) is the mixer, and (3
) is an intermediate frequency filter, (4) is an A/D converter, (6)
is a complex multiplier, (6) is an adder, (7) is a received signal output terminal, (8) is a reference signal input terminal, (9) is a miscalculation detection circuit, αq is a load control circuit, and (b) is a detection circuit. circuit, (6) is a baseband filter, (to) is a synchronization detection circuit, α is a homping synchronization search circuit, (g) is a clock input terminal, (to) is a frequency synthesizer, αη is a control condition setting switch, aB is an initial condition memory circuit, and is a code correlator. Note that the same reference numerals in Figure 1 indicate the same or equivalent parts. Fig. 1 Fig. 2 Fig. 1γ

Claims (1)

[Claims] (1) In an adaptive antenna system for FH communication that combines an adaptive antenna and an FH communication device that performs synchronization acquisition using a preamble signal at the initial stage of communication, adaptive control at the time of FH synchronization is constrained, and the initial stage of the above adaptive control is An adaptive antenna system for FH communication, characterized in that a value is set to a required value.