JPH1127251A - Frame synchronizing control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frame synchronizing control device for improving multipath fading resistance by controlling an aperture gate which allows detection of a synchronous word on the basis of a reception electric field intensity when the reception is performed in a time-division multiple radio system. SOLUTION: This device is provided with an electric field intensity measuring circuit 6 for measurement, performs a state transition by a synchronizing word detection and slightly widens a width of an aperture gate when the electric field intensity exceeds a fixed value in executing a burst reception in a reception synchronizing state. Thus, a synchronizing word can be detected because the width of the aperture gate is not exceeded even when a place of the synchronizing word deviates from a whole slot by a multipath, and a fine frame synchronization is obtained and a higher quality speech is made possible because a reception state can maintain the synchronizing state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame synchronization control apparatus in a digital radio communication system of a time division multiplex communication system.

[0002]

2. Description of the Related Art Conventionally, in mobile communication, when one frequency is divided into a plurality of frames on a time axis and each is assigned to a different station, frame synchronization is established when a TDMA (Time Division Multiplexing Communication) system is used. A synchronization word is used to do this. The reception circuit detects the position of the data in one burst by detecting the synchronization word, thereby enabling the reception data processing operation.

Hereinafter, a conventional frame synchronization control circuit will be described with reference to the drawings. FIG. 3 is a configuration diagram of a conventional frame synchronization control device. In FIG. 3, 1 is a wireless unit, 2 is a synchronous word detector, 3 is a reception state transition circuit,
Reference numeral 4 denotes an aperture gate control circuit, and reference numeral 5 denotes a reception synchronization control circuit including a reception state transition circuit 3 and an aperture gate control circuit 4.

The operation of the conventional frame synchronization control circuit configured as described above will be described below. In the normal synchronization state, the data demodulated by the radio unit 1 is input to the synchronization word detector 2, and the detection operation is performed only during the period when the aperture gate signal from the aperture gate control circuit 4 is "1". When the synchronization word is detected, a synchronization word detection signal is input to the reception state transition circuit 3. The reception synchronization control circuit 5 has a timer therein, and holds the timing at which the synchronization word detection signal is input until the next slot. In the next reception slot, the reception synchronization control circuit 5 has a narrow range with respect to the synchronization word detection timing. The aperture gate is controlled so as to be "1" for a certain period before and after and "0" for other periods, thereby reducing the establishment of synchronization word detection at positions where synchronization words should not be detected.

As described above, the synchronous word detector 2 detects the synchronous word within the narrowed aperture gate, and when the synchronous word cannot be detected, the synchronous word detector 2 shifts to the asynchronous state via the forward protection state.

[0006]

However, in the above-mentioned conventional method, when the position of the synchronization word moves beyond the aperture width due to the influence of multipath or the like, despite the fact that the received electric field strength is sufficient, the synchronization is not sufficient. If a word is not detected and the state continues thereafter, the state becomes an asynchronous state, and there is a problem that a synchronization word cannot be detected and frame synchronization cannot be performed until control is transferred to a wide aperture gate.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a frame synchronization control device capable of obtaining high quality frame synchronization control by performing aperture gate control while reflecting information of a radio wave state in state transition. .

[0008]

According to a first aspect of the present invention, there is provided a radio section for demodulating an input received radio wave and outputting burst data, detecting a synchronization word for the input burst data, and detecting the detection. A synchronization word detector that outputs a synchronization word detection signal based on the result, and a reception state transition that determines a transition of a frame synchronization state based on the detection signal from the synchronization word detector and outputs a state signal in the determined state. And a reception synchronization control circuit including an aperture gate control circuit that performs aperture control corresponding to the state signal on the synchronization word detector, and controls an aperture gate width for the synchronization word detector in a synchronization state. Variable control.

According to a second aspect of the present invention, there is provided an electric field strength measuring circuit for measuring the electric field strength of a radio wave input to the radio section, and an aperture gate for outputting from the reception state transition circuit to the synchronous word detector. Control is performed based on the value of the electric field strength.

[0010]

According to the first aspect of the present invention, there is provided a radio section for demodulating an input received radio wave and outputting burst data, detecting a synchronization word with respect to the input burst data, and detecting a synchronization word based on the detection result. A synchronization word detector that outputs a synchronization word detection signal, a reception state transition circuit that determines a transition of a frame synchronization state based on a detection signal from the synchronization word detector, and outputs a state signal in the determined state. An aperture gate control circuit for performing aperture control corresponding to the state signal on the synchronous word detector, and variably controls an aperture gate width for the synchronous word detector in a synchronous state. So that the aperture gate can be varied for each slot according to the synchronization state, It can be established.

According to a second aspect of the present invention, there is provided the frame synchronization control apparatus according to the first aspect, further comprising an electric field intensity measuring circuit for measuring an electric field intensity of a radio wave input to the radio section, and synchronizing from the reception state transition circuit. Since the aperture gate output to the word detector is controlled based on the electric field strength value, high-quality frame synchronization control is achieved by performing frame synchronization by reflecting the radio wave state information in the state transition. Can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows Embodiment 1 of the present invention.
And FIG. 2 is a state transition diagram in Embodiment 1 of the present invention. In FIG. 1, 1 is a radio unit, 2 is a synchronous word detector, 3 is a reception state transition circuit, 4 is an aperture gate control circuit, 5 is a reception synchronization control circuit including a reception state transition circuit 3 and an aperture gate control circuit 4, Reference numeral 6 denotes an electric field strength measurement circuit.

The operation of the frame synchronization control device configured as described above will be described below. The burst data demodulated by the radio unit 1 is input to the synchronization word detector 2 and outputs a detection signal to the reception state transition circuit 3 when the synchronization word can be detected. The receiving state transition circuit 3 which has received the detection signal transitions from the asynchronous state to the synchronous state via the backward protection state by detecting the synchronous word continuously based on the state transition diagram shown in FIG. In the synchronized state, the reception state transition circuit 3 adjusts the width of the aperture gate by providing a state control signal to the aperture gate control circuit 4. Normally, the aperture gate is set in a narrow range in the synchronous state. However, when the electric field intensity data from the electric field intensity measurement circuit 6 is received and exceeds a certain value, the previous burst and the reception timing due to multipath fading or the like are caused. It is determined that demodulation is sufficiently possible even if is different, and the width of the aperture gate is controlled to be wider so that even a slight displacement of burst data can be received without exceeding the aperture range.

[0014]

According to the present invention, since the data from the received electric field strength can be added to the reception state transition, the aperture gate is widened when the electric field strength is sufficiently large in the synchronous state, thereby synchronizing with extreme multipath fading. It is possible to prevent non-detection of words, and to obtain good frame synchronization.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a frame synchronization control device according to a first embodiment of the present invention.

FIG. 2 is a state transition diagram according to the first embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional frame synchronization control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Radio part 2 Synchronous word detector 3 Reception state transition circuit 4 Aperture gate control circuit 5 Reception synchronization control circuit 6 Electric field strength measurement circuit

Claims (2)

[Claims] 1. A radio unit for demodulating an input received radio wave and outputting burst data, and a sync word detector for detecting a sync word for the input burst data and outputting a sync word detection signal based on the detection result. A receiving state transition circuit for determining a transition of a frame synchronization state based on a detection signal from the synchronization word detector, and outputting a state signal in the determined state; A frame synchronization control device, comprising: a reception synchronization control circuit including an aperture gate control circuit for performing aperture control corresponding to a signal, and variably controlling an aperture gate width for the synchronization word detector in a synchronization state. 2. An electric field intensity measuring circuit for measuring electric field intensity of a radio wave input to the radio section, wherein control of an aperture gate output from the reception state transition circuit to the synchronous word detector is controlled to a value of electric field intensity. 2. The frame synchronization control device according to claim 1, wherein control is performed based on the frame synchronization.