KR100240284B1 - Modified space diversity receiving apparatus - Google Patents

Abstract

According to the present invention, the Modified Space Diversity allows the variable phase shifter to operate normally even when the strength of the signal applied from each antenna is weak. It relates to a receiving device.

The phase comparator of the conventional space diversity receiver may have an error and a malfunction during phase comparison when the signal level received through the two antennas is very low.

In this case, since the variable phase shift does not find a predetermined value properly, the shift continues, and as a result, an error occurs when combining signals in the combiner.

In order to solve this problem, the present invention detects the phase of the signal strength from the intermediate frequency obtained from the signal received from the first antenna ANT1 and the intermediate frequency obtained from the signal received from the second antenna ANT2 and adjusts the phase of the two signals. Generates a phase control signal according to the phase comparator to be compared, the in-phase detection signal output from the phase comparator, and the first and second automatic gain controllers controlling the gains of the two intermediate frequency signals. Control logic; A phase controller for selectively outputting an output value of the phase comparator or a previous phase control value according to control of control logic; It is composed of a variable phase shifter for varying the phase of the frequency output through the frequency divider in accordance with the phase control signal selectively output from the phase control unit.

Description

Modified Space Diversity Receiver

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Modified Space Diversity receiver, and in particular, that a variable phase shifter operates normally even when the strength of a signal applied from each antenna is weak. The present invention relates to a Modified Space Diversity receiver which eliminates the occurrence of an error in the system.

In the conventional space diversity receiver, as shown in FIG. 1, the first low noise amplifier 3 outputs low-frequency amplification of a high frequency received through the first antenna 1 to a predetermined level. And a second low noise amplifier 4 for low noise amplifying and outputting a high frequency received through the second antenna 2 to a predetermined level, a local oscillator 5 for generating an oscillation frequency, and the local oscillator 5 A frequency division part 6 for dividing the oscillation frequency generated at the predetermined level and a frequency divided through the frequency division part 6 according to a phase control signal output from the phase control part 19. A phase shifter 7 and a frequency divided by the frequency divider 6 and a low noise frequency output from the first low noise amplifier 3 are mixed to down-convert and then converted to an intermediate frequency. A first mixing section 8 and the variable phase shift A second mixing unit 10 for converting the frequency variable and output from the unit 7 and the low noise amplified frequency through the low noise amplifier 4 to down-convert and converting the intermediate frequency into an intermediate frequency; The first intermediate frequency amplifier 9 amplifies and outputs the intermediate frequencies mixed through the first mixing unit 8 to a predetermined level, and the intermediate frequencies mixed through the second mixing unit 10 are predetermined. A second intermediate frequency amplifier 11 for amplifying and outputting at a level; a first band filter unit 12 for filtering and outputting only a predetermined band at an intermediate frequency output from the first intermediate frequency amplifier 9; The second band filter unit 13 for filtering and outputting only a predetermined band from the intermediate frequency output from the second intermediate frequency amplifying unit 11 and the intermediate frequency filtered through the first band filter unit 12 are predetermined. A third intermediate frequency amplifier 14 for amplifying and outputting at a level of? A fourth intermediate frequency amplifier 15 for amplifying and outputting the intermediate frequency filtered by the second band filter unit 13 to a predetermined level, and outputting the third intermediate frequency amplifier 14. A first automatic gain control unit 16 which detects an intermediate frequency and controls gain, a second automatic gain control unit 17 which detects an intermediate frequency output from the fourth intermediate frequency amplifier 15 and controls gain; A phase comparator 18 for comparing the phases of the intermediate frequencies output from the third intermediate frequency amplifier 14 and the fourth intermediate frequency amplifier 15 and outputting the result values, and the phase comparison unit In the phase control unit 19 for comparing the signal output from the (18) with a predetermined error value and generates a variable phase control signal according to the result, and in the first and second intermediate frequency amplification unit (9) (11) Combiner unit 20 for synthesizing and outputting the respective intermediate frequencies and the combiner And a fifth intermediate frequency amplifier 21 for amplifying the synthesized frequency to a predetermined level according to the level control signal of the level detector 22 and outputting the frequency to the intermediate frequency output terminal IF-OUT. .

The operation of a conventional space diversity receiver configured as described above will be described with reference to FIG. 1.

First, the first and second low noise amplifiers 3 and 4 amplify the high frequency signals received through the first and second antennas 1 and 2 to a predetermined level so that the first and second mixing units ( 8) to (10).

On the other hand, the divider 6 divides the oscillation frequency generated by the local oscillator 5 to a predetermined level and outputs the oscillation frequency to the first mixing unit 8.

Then, the first mixing unit 8 mixes the high frequencies output from the first low noise amplifier 3 and the dividing unit 6, down-converts them, converts them to intermediate frequencies, and then converts them into intermediate frequencies. It outputs to the frequency amplification part 9.

In addition, the second mixing unit 10 converts the low noise frequency output from the low noise amplifier 4 and the frequency output through the variable phase shifter 7 to down-convert and then converts into an intermediate frequency. To be output to the second intermediate frequency amplifier 11.

Then, the first and second intermediate frequency amplifiers 9 and 11 amplify the intermediate frequencies output from the first and second mixing units 8 and 10 to a predetermined level so as to combine the combiner 20. Will print out each one.

Accordingly, the combiner 20 synthesizes the intermediate frequencies output from the first and second intermediate frequency amplifiers 9 and 11 and outputs the synthesized intermediate frequencies to the fifth intermediate frequency amplifier 21.

Accordingly, the fifth intermediate frequency amplifier 21 amplifies the intermediate frequency synthesized through the combiner 20 to a predetermined level according to the level control signal of the level detector 22 to output the intermediate frequency output stage IF OUT. Will print to

However, each intermediate frequency applied to the combiner portion 20 increases in signal strength when synthesized only when the phases are matched.

Therefore, the phase of these two signals is matched through the phase comparator 17, the phase controller 18, and the variable phase shifter 7.

That is, when the phase difference between the two signals to be mixed in the phase comparator 18 is greater than a predetermined error, the phase controller 19 adjusts the phase shift value of the variable phase shifter 7 so that the phases of the two signals are equal. Controlled.

However, the phase comparator of the conventional space diversity receiver may have errors and malfunctions during phase comparison when the level of signals received through the two antennas is very low.

In this case, the variable phase shift does not find a predetermined value properly and continues to shift, resulting in an error in combining signals in the combiner.

Therefore, the present invention provides a modified space diversity function that allows a variable phase shifter to operate normally even when the strength of a signal applied from each antenna is weak, thereby eliminating an error in the combination. The purpose is to provide a receiving device.

Technical means for achieving this object is to detect the phase of the signal strength from the intermediate frequency obtained from the signal received from the first antenna (ANT1) and the intermediate frequency obtained from the signal received from the second antenna (ANT2) and Phase control according to a phase comparator for comparing phases, an output of the in-phase depth signal output from the phase comparator and the first and second automatic gain controllers controlling gains of the two intermediate frequency signals. A control logic for generating a signal; A phase controller for selectively outputting an output value of the phase comparator or a previous phase control value according to the control of the control logic; According to the phase control signal selectively output from the phase control unit is composed of a variable phase shifter for varying the phase of the frequency output through the divider and output.

1 is a block diagram of a conventional space diversity receiver.

2 is a block diagram of a Modified Space Diversity receiver according to the present invention.

3 is a detailed circuit diagram of each part of FIG.

* Explanation of symbols for main parts of the drawings

117: phase comparison unit 118: first automatic gain control unit

119: second automatic gain control unit 120: control logic

121: phase control unit 120a: or gate

120b: AND gate 121a: counter

121b: ROM (ROM) 121c: first digital / analog converter

121d: second digital / analog converter

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a block diagram of a modified space diversity receiver according to the present invention. The first diagram for low noise amplifying and outputting a high frequency received through a first antenna ANT1 to a predetermined level is shown in FIG. A low noise amplifier 101, a second low noise amplifier 102 for low noise amplifying and outputting a high frequency received through the second antenna ANT1 to a predetermined level, a local oscillator 110 for generating an oscillation frequency, and The frequency division unit 111 divides the oscillation frequency generated by the local oscillation unit 110 to a predetermined level, and divides the phases through the division unit 111 according to a phase control signal selectively output from the phase control unit 121. A variable phase shifter 112 for varying and outputting the phase of the frequency, and the frequency divided by the frequency divider 111 and the low noise frequency output from the first low noise amplifier 101 to down-convert ( The first mixing unit 103 for converting to the intermediate frequency after the down conversion, and the variable frequency output from the variable phase shifter 112 and the low noise amplified frequency through the second low noise amplifier 102 A second mixing unit 104 that mixes and converts down to an intermediate frequency, and a first intermediate frequency that amplifies and outputs an intermediate frequency mixed through the first mixing unit 103 to a predetermined level. A second intermediate frequency amplifier 106 for amplifying and outputting an intermediate frequency mixed by the amplifier 105 and the mixer second mixer 104 to a predetermined level, and the first intermediate frequency amplifier 105 A first band filter unit 113 for filtering and outputting only a predetermined band at an intermediate frequency output from the second band), and a second filter for filtering only a predetermined band at an intermediate frequency output from the second intermediate frequency amplifier 106. Band filter unit 114 and the first band filter unit 113 A third intermediate frequency amplifier 115 for amplifying and outputting the filtered intermediate frequency to a predetermined level, and amplifying and outputting the intermediate frequency filtered through the second band filter unit 114 to a predetermined level. The first automatic gain control unit 118 detects the intermediate frequency output from the quadrature frequency amplifying unit 116 and the third intermediate frequency amplifying unit 115 to automatically control a weak gain, and generates a level alarm signal. And a second automatic gain control unit 119 which detects an intermediate frequency output from the fourth intermediate frequency amplifying unit 116 to automatically control a weak gain, and generates a level alarm signal, and the third intermediate point. A phase comparator 117 for detecting the phase of signal strength from the intermediate frequencies obtained by the frequency amplifying unit 115 and the fourth intermediate frequency amplifying unit 116 and comparing the phases of the two signals; Phase Detection Output from 117 (In A control logic (120) for generating a phase control signal in accordance with an output of the first and second automatic gain controllers (118, 119) controlling the gain of the phase delay signal and the two intermediate frequency signals; A phase control unit 121 selectively outputs the output value of the phase comparison unit 117 or the previous phase control value according to the control of the control unit 120.

In the above, the control logic 120 is an OR gate 120a for ORing and outputting a level alarm signal respectively output from the first and second automatic gain control units 118 and 119, and the or gate. The AND gate 120b outputs a phase control signal by ANDing the signal output from the signal 120a and the phase detection signal In-Phase Detect output from the phase comparator 117.

In addition, the phase controller 121 up / down counts the signal Lead-Lag output from the phase comparator 117 according to the phase control signal output from the control logic 120 and outputs the counter 121a. And a ROM 121b for searching for a signal output from the counter 121a and selectively outputting an output value or a previous phase control value of the phase comparator 117 according to the search result, and in the ROM 121b. The first and second digital / analog converters 121c and 121d convert the output phase control value into an analog signal and output the same.

Referring to Figures 2 and 3 attached to the operation and effect of the present invention configured as described above are as follows.

First, the first and second mixers ANT1 and ANT2 receive a low noise amplification at a predetermined level by the first and second low noise amplifiers 101 and 102. Output to 103) 104.

Meanwhile, the divider 111 divides the oscillation frequency generated by the local oscillator 110 to a predetermined level and outputs the oscillation frequency to the first mixer 103 and the variable phase shifter 112, respectively.

Then, the first mixing unit 103 converts the high frequency low noise amplified by the first low noise amplifier 101 and the frequency divided by the frequency divider 111 to down-convert and converts it into an intermediate frequency. To be output to the first intermediate frequency amplifier 105.

In addition, the second mixing unit 104 down-converts by mixing the high frequency low-noise amplified by the second low noise amplifier 102 and the variable frequency output through the variable phase shifter 112. Converted to the intermediate frequency and output to the second intermediate frequency amplifier 106.

Then, the first and second intermediate frequency amplifiers 105 and 106 amplify the intermediate frequencies output from the first and second mixing units 103 and 104 to a predetermined level, respectively, and the combiner unit 107. Will print).

In this case, the first and second band filter units 113 and 114 filter and output only a predetermined band at an intermediate frequency output from the first and second intermediate frequency amplifiers 105 and 106.

Accordingly, the third intermediate frequency amplifier 115 amplifies the intermediate frequency filtered by the first band filter 113 to a predetermined level and outputs the result to the phase comparator 117.

In addition, the fourth intermediate frequency amplifier 116 amplifies the intermediate frequency filtered by the second band filter 114 to a predetermined level and outputs the result to the phase comparator 117.

In this process, the first and second automatic gain control units 118 and 119 detect a weak intermediate frequency signal output from the third and fourth intermediate frequency amplifying units 115 and 116 to control gain. In addition, the level alarm control signal is output to the control logic 120.

Accordingly, the phase comparison unit 117 detects the phase of the signal strength from the intermediate frequencies obtained by the third and fourth intermediate frequency amplifiers 115 and 116, respectively, compares the phases of the two signals, and outputs the result. Done.

Then, the control logic 120 is the first and second automatic gain control unit 118 for controlling the gain of the phase detection (In-Phase Detect) signal and the two intermediate frequency signals output from the phase comparator 117 ( A phase control signal is generated according to the output of 119.

That is, the or gate 120a in the control logic 120 logically sums the level alarm signals output from the first and second automatic gain control units 118 and 119 and outputs them to the AND gate 120b. Done.

Then, the AND gate 120b outputs a phase control signal by ANDing the signal output from the or gate 120a and the phase detection signal In-Phase Detect output from the phase comparator 117.

Accordingly, the phase controller 121 selectively outputs the output value of the phase comparator 117 or the previous phase control value according to the control of the control logic 120.

That is, the counter 121a in the phase controller 121 up / down counts the signal Lead-Lag output from the phase comparator 117 according to the phase control signal output from the control logic 120. It outputs to 121b.

Then, the ROM 121b searches for the signal output from the counter 121a, and selectively outputs the output value of the phase comparator 117 or the previous phase control value according to the search result, so that the first and second digital / The analog conversion unit 121c or 121d converts the analog signal to output a phase control signal.

Accordingly, the variable phase shifter 112 adjusts the phase shift value of the frequency divided by the divider 111 according to the phase control signal output from the phase controller 121 so that the phases of the two signals become equal. will be.

That is, conventionally, when the phase detection signal (In-Phase Detect) output from the phase comparator is turned on, the counter in the phase control unit immediately changes to a disabled state. However, the phase comparator 121 here uses the first, Phase only when the level of the two signals mixed by using the level alarm signal input from the second automatic gain control unit 118 or 119 and the phase detection signal (In-Phase Detect) input from the phase comparing unit 117 is normal. If the detection signal (In-Phase Detect) operates and either of the signals has a low level, the counter 121a in the phase control unit 121 is unconditionally disabled, so it is fixed to the final value in normal operation. Will be.

As described above, in the present invention, when a weak signal received through an antenna is recognized in advance and a signal is sent to the control logic, the control logic searches for the signal and outputs a signal for the final value when the phase controller is normally operated. By sending it to the Phase Shifter), it is effective to eliminate the occurrence of error during combining.

Claims (3)

Phase comparator 117 for detecting the phase of the signal strength from the intermediate frequency obtained from the signal received from the first antenna ANT1 and the intermediate frequency obtained from the signal received from the second antenna ANT2 and comparing the phases of the two signals. Wow; Phase control according to the outputs of the first and second automatic gain controllers 118 and 119 controlling the gain of the in-phase detection signal and the two intermediate frequency signals output from the phase comparator 117. A control logic 120 for generating a signal; A phase controller 121 for selectively outputting an output value of the phase comparator 117 or a previous phase control value according to the control of the control logic 120; Modified characterized in that it comprises a variable phase shifter 112 for outputting the phase of the frequency output through the frequency divider 111 in accordance with the phase control signal selectively output from the phase control unit 121 Space Diversity Receiver. 2. The control logic circuit 120 of claim 1, wherein the control logic 120 includes an orgate 120a for logically combining and outputting a level alarm signal output from the first and second automatic gain control units 118 and 119, respectively. And an AND gate (120b) for outputting a phase control signal by ANDing the signal output from the or gate (120a) and the phase detection signal (In-Phase Detect) output from the phase comparing unit (117). Modified Space Diversity Receiver. According to claim 1, The phase control unit 121 outputs by counting up / down the signal (Lead-Lag) output from the phase comparison unit 117 according to the phase control signal output from the control logic 120 And a ROM 121b for searching for a signal output from the counter 121a and selectively outputting an output value or a previous phase control value of the phase comparator 117 according to the search result. Modified Space Diversity, characterized in that the first, second digital / analog converter (121c) (121d) for converting the phase control value output from the ROM (121b) and outputs the analog signal Receiver.

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