KR102175387B1 - Apparatus and method for half duplex wireless repeaters - Google Patents

Abstract

The present invention relates to a half-duplex wireless relay apparatus and method.
A half-duplex wireless relay apparatus according to the present invention includes: an antenna switching unit for setting a transmission path or a reception path for a plurality of antennas; A receiving circuit unit for receiving an analog signal transmitted from the antenna switching unit; An AD conversion unit converting the received analog signal into a digital signal; A signal delay unit delaying the converted digital signal for a preset delay time; A DA conversion unit converting the delayed digital signal into an analog signal; And a transmission circuit unit for transmitting the converted analog signal to the antenna switching unit.

Description

Apparatus and method for half duplex wireless repeaters}

The present invention relates to a half-duplex wireless relay apparatus and method, and more particularly, to a half-duplex wireless relay apparatus and method for relaying communication devices using a half-duplex wireless communication method, such as a radio.

A wireless relay device is an equipment used to eliminate a shadow area in an area where communication is required, and facilitates communication between a base station and a terminal (mobile station) or between a terminal and a terminal. In recent years, with the development of mobile communication, many relay devices have been developed and used to resolve shadow areas in the mobile communication service area, and the technology has also made remarkable developments.

On the other hand, the traditional wireless communication method, radio, is still used as an essential communication method in various industrial sites. Recently, the importance of the wireless communication auxiliary equipment has been strengthened due to the securing of the national disaster safety communication network and the reinforcement of fire safety standards. . However, the development and use of a relay device for a radio or broadcast service using a half-duplex communication method is relatively weak compared to mobile communication.

Conventional technologies related to the half-duplex wireless relay device include Korean Patent No. 10-1097406 (a wireless relay device and method for single-frequency short communication), and Korean Patent No. 10-1736244 (emergency disaster communication system).

These prior art are separately provided with a first signal processing unit (transmitting/receiving circuit unit) for transmitting signals from a first mobile station to a second mobile station and a second signal processing unit (transmitting/receiving circuit unit) for transmitting signals from the second mobile station to the first mobile station. , Turning on/off the first and second signal processing units (transmitting/receiving circuit units) of the wireless relay device by using the hook signals of the first and second mobile stations as synchronization signals.

However, in the prior art, a synchronization signal detection unit, a signal processing unit (transmitting/receiving circuit unit), and the like for the first path for transmitting signals from the first mobile station to the second mobile station and the second path for transmitting signals from the second mobile station to the first mobile station, respectively. Since it is equipped with, there is a problem of high complexity and low economic efficiency by implementing the same circuit redundantly.

In particular, in recent years, digital radios capable of not only voice communication but also text communication or data communication have been commercialized.Since the conventional technology uses the hook signal of a mobile station as a synchronization signal, text communication or data communication cannot be used in the case of digital radios. There was a problem that voice communication could also be limited.

Korean Patent Publication No. 10-1097406 Korean Patent Publication No. 10-1736244

The present invention was devised to solve the above-described problems, and an object of the present invention is to be easily implemented with one wireless relay device without increasing the complexity of the circuit even when multiple antennas are used due to the large number of shaded areas. It is to provide a half-duplex wireless relay apparatus and method.

Another object of the present invention is to provide a half-duplex wireless relay apparatus and method that can be applied not only to an analog radio for performing only voice communication but also to a digital radio for performing text communication or data communication.

Another object of the present invention is to provide a half-duplex wireless relay apparatus and method for converting an analog signal received from an antenna into a digital signal, delaying the digital signal for a preset delay time, and then transmitting it.

Another object of the present invention is to provide a half-duplex wireless relay apparatus and method capable of relaying a radio signal received through an arbitrary antenna without loss even when several antennas are switched to a transmission path or a reception path.

For the above purposes, a half-duplex wireless relay apparatus according to an embodiment of the present invention includes: an antenna switching unit for setting a transmission path or a reception path for a plurality of antennas; A receiving circuit unit for receiving an analog signal transmitted from the antenna switching unit; An AD conversion unit converting the received analog signal into a digital signal; A signal delay unit delaying the converted digital signal for a preset delay time; A DA conversion unit converting the delayed digital signal into an analog signal; And a transmission circuit unit for transmitting the converted analog signal to the antenna switching unit.

In addition, a half-duplex wireless relay device according to another aspect of the present invention includes an antenna switching unit for setting a transmission path or a reception path for first and second antennas, respectively; A receiving circuit unit configured to amplify at least one of the first and second analog signals with a first amplification degree by receiving the first analog signal received through the first antenna and the second analog signal received through the second antenna; An AD converter for converting the at least one amplified first and second analog signals into digital signals; A signal delay unit delaying the converted digital signal for a preset delay time; A DA conversion unit converting the delayed digital signal into an analog signal; A transmission circuit unit for transmitting the converted analog signal to the antenna switching unit; A signal detection unit detecting whether there is a radio signal from the converted digital signal; And when a radio signal is detected by the signal detector, the first amplification level is adjusted to determine a signal including the radio signal among the first and second analog signals, and a reception path is set for an antenna receiving the radio signal. And a control unit for controlling the antenna switching unit to set a transmission path for an antenna that does not receive the radio signal.

In addition, a half-duplex wireless relay apparatus according to another aspect of the present invention includes: an antenna switching unit for setting a transmission path or a reception path for first and second antennas, respectively; A first receiving circuit unit for receiving a first analog signal through the first antenna and a second receiving circuit unit for receiving a second analog signal through the second antenna; A first AD conversion unit for converting a first analog signal output from the first receiving circuit unit into a first digital signal and a second AD conversion unit for converting a second analog signal output from the second receiving circuit unit into a second digital signal part; A signal delay unit delaying the first and second digital signals output from the first and second AD conversion units for a preset delay time; A DA conversion unit converting the digital signal output from the signal delay unit into an analog signal; A transmission circuit unit for transmitting the converted analog signal to the antenna switching unit; A first signal selection unit selecting one of the first and second digital signals output from the first and second AD conversion units; A signal detection unit detecting whether there is a radio signal from the digital signal selected by the signal selection unit; And when a radio signal is detected by the signal detection unit by controlling the first signal selection unit, a reception path is set for an antenna receiving the radio signal, and a transmission path is set for an antenna not receiving the radio signal. It characterized in that it comprises a control unit for controlling the antenna switching unit.

Meanwhile, a half-duplex wireless relay method according to an aspect of the present invention includes the steps of: receiving an analog signal through an arbitrary antenna among a plurality of antennas; Converting the received analog signal into a digital signal; Delaying the converted digital signal for a preset delay time; Converting the delayed digital signal into an analog signal; And transmitting the converted analog signal through the antennas other than the arbitrary antenna among the plurality of antennas.

In addition, a half-duplex wireless relay method according to another aspect of the present invention includes: receiving a first analog signal through a first antenna and receiving a second analog signal through a second antenna; Amplifying at least one of the first and second analog signals with a first amplification degree; Converting the at least one amplified first and second analog signals into digital signals; Delaying the converted digital signal for a preset delay time and adjusting the first amplification degree to determine an antenna for receiving a radio signal from among the first and second antennas; Converting the delayed digital signal into an analog signal; And transmitting the converted analog signal through an antenna that does not receive a radio signal among the first and second antennas.

In addition, a half-duplex wireless relay method according to another aspect of the present invention includes: receiving a first analog signal through a first antenna and receiving a second analog signal through a second antenna; Converting the first analog signal into a first digital signal and converting the second analog signal into a second digital signal; Delaying the first and second digital signals for a preset delay time, and determining a signal including a radio signal for the first and second digital signals; Converting a digital signal including a radio signal among the first and second digital signals into an analog signal; And transmitting the converted analog signal through an antenna that does not receive a radio signal among the first and second antennas.

According to the present invention, since the transmission/reception circuit is not provided for each path according to the antenna combination, but one common transmission/reception circuit is provided regardless of the number of antennas, the effect of implementing efficiently at low cost without increasing the complexity of the circuit is achieved. Have.

In addition, according to the present invention, after converting a plurality of analog signals received from a plurality of antennas into digital signals, by determining the antenna receiving the actual radio signal while delaying for a preset delay time, and setting the transmission/reception path accordingly , It has the effect of preventing loss of a signal to be relayed by delaying transmission until a correct transmission/reception path is established for a plurality of antennas. And, accordingly, it has an effect that can be applied to digital radios that perform text communication or data communication as well as analog radios that perform only voice communication.

1 is a block diagram of a half-duplex wireless relay apparatus according to a first embodiment of the present invention.
2 is a configuration diagram of an antenna switching unit according to an embodiment of the present invention.
3 is a block diagram of a receiving circuit unit according to an embodiment of the present invention.
4 is a configuration diagram of a signal detector according to an embodiment of the present invention.
5 shows an ROC curve (Receiver Operating Characteristic Curve) according to a change in SNR.
6 is a configuration diagram of a signal detector according to another embodiment of the present invention.
7 is a schematic diagram illustrating a method of detecting a signal using a plurality of narrowband filters.
8 shows an ROC curve (Receiver Operating Characteristic Curve) according to a change in the number of narrowband filters.
9 is a block diagram of a half-duplex wireless relay device according to a second embodiment of the present invention.
10 is a block diagram of a channel selection unit according to an embodiment of the present invention.
11 is a block diagram of a half-duplex wireless relay apparatus according to a third embodiment of the present invention.
12 is a block diagram of a half-duplex wireless relay apparatus according to a fourth embodiment of the present invention.
13 is a block diagram of a half-duplex wireless relay apparatus according to a fifth embodiment of the present invention.
14 is a block diagram of a receiving circuit unit according to another embodiment of the present invention.
15 shows a signal processing method in a half-duplex wireless relay apparatus according to a fifth embodiment of the present invention.
16 is a block diagram of a half-duplex wireless relay apparatus according to a sixth embodiment of the present invention.
17 shows a burst signal processing method of a digital radio in the half-duplex wireless relay device according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, detailed descriptions of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted in the following description.

The bandwidth per channel of a typical radio is about 5 kHz, 6.5 kHz, and 12.5 kHz, and these channels are set at a bandwidth of 10 MHz to 70 MHz (or more) at a bandwidth interval per channel. For example, according to the safety standards of domestic wireless communication auxiliary equipment, a frequency of 440 MHz to 450 MHz is used for half-duplex wireless communication, and a bandwidth of 12.5 kHz per channel is allocated for a frequency bandwidth of 10 MHz, so that a total of 800 channels can be used.

For these half-duplex wireless communication channels, the subject of use (e.g., government offices, companies, hospitals) is generally determined for each channel (frequency) according to business and use, and channels (frequency) approved for use at sites such as government offices, companies, and hospitals. Half-duplex wireless communication is performed by selecting one or more channels (frequency) from among them. Accordingly, radios that are actually used in each site are mainly manufactured so that only 5 to 30 limited channels (frequency) can be used, and as a result, half-duplex radio relay devices that relay these radios are in principle used in actual sites. It only needs to be implemented so that only a few channels (frequency) can be relayed.

However, in order to be applied and used in a variety of sites other than a specific site in which a channel to be used is designated, a half-duplex wireless repeater must be able to relay signals from radios for various purposes (ie, radios with different channels). Therefore, most half-duplex wireless repeaters including the prior art are implemented in a manner that passes the entire half-duplex wireless communication frequency band or the entire band supported by the radio for various purposes (for example, a 40MHz band of 420MHz to 460MHz). And, even though it is implemented by passing only some frequency bands (e.g., 10 MHz bands of 440 MHz to 450 MHz) including the channel to be relayed (frequency), it is not used between and/or adjacent to the channels to be relayed (frequency). Channels (frequency) were also included. As a result, the half-duplex wireless repeater according to the prior art could not lead to optimal performance, and it was difficult to implement high precision due to the limitation of the analog bandpass filter.

On the other hand, the half-duplex wireless relay device according to the prior art, as described above, for a first path for transmitting a signal from a first mobile station to a second mobile station and a second path for transmitting a signal from the second mobile station to the first mobile station. Each includes a synchronization signal detection unit, a signal processing unit (transmission/reception circuit unit), and the like. Accordingly, the same circuit is implemented redundantly in the first path and the second path, resulting in high complexity and low economic efficiency. And, since the half-duplex wireless repeater according to the prior art has only two antennas, when there are several shaded areas (for example, when three or more antennas are required), several wireless repeaters (main donor and one The above sub-donors) are interlocked. As a result, in the prior art, when there are several shaded areas, installation is difficult and costs are high.

Hereinafter, a half-duplex wireless relay apparatus and method according to the present invention will be described in detail with reference to FIGS. 1 to 17.

First, FIG. 1 is a block diagram of a half-duplex wireless relay device according to a first embodiment of the present invention.

Referring to FIG. 1, a half-duplex wireless repeater 100 according to a first embodiment of the present invention includes an antenna switching unit 110, a receiving circuit unit 120, an AD conversion unit 130, a signal detection unit 140, And a control unit 150, a signal delay unit 170, a DA conversion unit 180, a transmission circuit unit 190, and the like.

The antenna switching unit 110 is connected to a plurality of antennas 101 and 102, and when a signal is received through an antenna among a plurality of antennas, it transmits the signal to the receiving circuit unit 120 and undergoes filtering, amplification, etc. The signal output from the transmission circuit unit 190 is transmitted to the remaining antennas among the plurality of antennas. For example, the antenna switching unit 110 is composed of a switch or the like as shown in FIG. 2, and when a signal is received from the first antenna 101, the signal is transmitted to the receiving circuit unit 120 and the transmitting circuit unit 190 The signal output from the second antenna 102 is transmitted to the second antenna 102, and when a signal is received from the second antenna 102, it is transmitted to the receiving circuit unit 120, and the signal output from the transmitting circuit unit 190 is transmitted to the first antenna 101. ). For reference, although a form having two antennas 101 and 102 is illustrated in FIG. 1, a form having three or more antennas is of course possible.

The reception circuit unit 120 removes components unnecessary for AD (Analog to Digital) conversion of the signal transmitted from the antenna conversion unit 110, amplifies the signal to an appropriate size for AD conversion, and then sums and outputs the result. For example, the receiving circuit unit 120 may include a low noise amplifier (LNA) 122', 122', a band pass filter (BPF) 124', 124'), as shown in FIG. It is composed of a variable gain amplifier (VGA; Variable Gain Amplifier) 126', 126", etc., and a frequency band for half-duplex wireless communication for analog signals transmitted from the antenna switching unit 110 (for example, a 40MHz band of 420MHz to 460MHz) ) Or a partial band (eg, a 10MHz band of 440MHz to 450MHz) is passed (filtered) to remove unnecessary components for AD conversion and amplify it to a size suitable for AD conversion. Transitions the filtered analog signal to an intermediate frequency (IF) or a baseband, and amplifies it to a size suitable for AD conversion. For reference, in the case of the reception circuit unit 120 shown in FIG. 3, antenna conversion After receiving the first analog signal received from the unit 110 through the first antenna 101, passing through the first low noise amplifier 122' and the first bandpass filter 124', the first variable gain amplifier 126 ') is amplified by the first amplification level, and similarly, a second analog signal received through the second antenna 102 from the antenna switching unit 110 is received, and a second low noise amplifier 122" and a second bandpass filter ( 124"), the second variable gain amplifier 126" is amplified with a second amplification level, and these signals are summed and output through one path. In this case, the amplification degrees of the variable gain amplifiers 126 ′ and 126 ″ may be controlled by the control unit 150, and accordingly, a plurality of analog signals input to the receiving circuit unit 120 may be amplified with different amplification degrees. .

The AD conversion unit 130 converts an analog signal output from the reception circuit unit 120 into a digital signal. For example, the AD converter 130 is composed of a sampler, a quantizer, etc., and samples the analog signal transmitted from the receiving circuit unit 120 while maintaining the phase and amplitude as it is. It quantizes to generate a digital signal.

The signal detection unit 140 determines whether there is a signal (radio signal) to be relayed from the digital signal output from the AD conversion unit 130, and transmits the result (signal detection result) to the control unit 150. Specific functions and features of the signal detection unit 140 according to the present invention will be described in detail below.

The control unit 150 determines the presence or absence of a radio signal based on the signal detection result transmitted from the signal detection unit 140, and if there is a radio signal, the controller 150 sets a reception path for the antenna currently receiving the radio signal, and The antenna switching unit 110 is controlled to set a transmission path for the other antennas. For example, the control unit 150 controls the reception circuit unit 120 (specifically, a variable gain amplifier, see Fig. 3) to have the same degree of amplification for each signal received from the plurality of antennas 101 and 102 in the standby state. Then, when the radio signal is detected from the signal detection result of the signal detection unit 140, the reception circuit unit 120 is controlled to sequentially change the amplification degree for each signal received from the plurality of antennas 101 and 102. Thus, the antenna in which the actual radio signal is received is identified by a method of checking the size change calculated by the signal detector 140. Further, the control unit 150 controls the antenna switching unit 110 so that the connection with the reception circuit unit 120 is maintained for the antenna currently receiving the radio signal, and the transmission circuit unit 190 is connected to the remaining antennas. For reference, in the case of the receiving circuit unit 130 shown in FIG. 3, first and second variable gain amplifiers 126' and 126' are used for each of the signals received from the first and second antennas 101 and 102. Thus, the first and second amplification degrees are adjusted. One antenna, for example, the first antenna 101, does not use a variable gain amplifier (in this case, the amplification degree corresponds to 1) and the remaining antennas, for example, the second antenna ( If a variable gain amplifier is used only for 102), the antenna from which the actual radio signal is received can be identified, and the variable gain amplifier may be any means such as a variable attenuator that can adjust the amplification of the circuit.

Meanwhile, the signal delay unit 170 is provided between the AD conversion unit 130 and the DA conversion unit 180 to delay the digital signal output from the AD conversion unit 130 for a preset delay time, and then the DA conversion unit ( 180). For example, the signal delay unit 170 is composed of a memory or the like and temporarily stores a digital signal (digital data) transmitted from the AD conversion unit 130 for a preset delay time, and then transfers it to the DA conversion unit 180. In this case, the delay time in the signal delay unit 170 is required until the control unit 150 controls the state of the antenna switching unit 110 by radio signal detection after the signal is input to the AD conversion unit 130. It is preferable to set the time to be. In addition, the signal delay unit 170 may have a scaling function of inversely compensating an amplification degree intentionally changed by the control unit 150 through the reception circuit unit 120 in order to distinguish a received antenna.

The DA conversion unit 180 converts the digital signal output from the channel selection unit 160 into an analog signal. For example, the DA conversion unit 180 is composed of a resistor, an operational amplifier, and the like, and generates an analog signal corresponding to a digital signal output from the signal delay unit 160.

The transmission circuit unit 190 amplifies power after removing unnecessary components from the analog signal output from the DA conversion unit 180 and transmits the amplified power to the antenna conversion unit 190. For example, the transmission circuit unit 190 is composed of a band-pass filter, a power amplifier, etc., and amplifies it into power that can be transmitted by the antenna after removing unnecessary components from the analog signal output from the DA conversion unit 180 Then, it is transmitted to the antenna switching unit 190. In addition, the transmission circuit unit 190, if the frequency is shifted in the reception circuit unit 120 or the output frequency of the DA converter 180 is different from the frequency to be transmitted, the frequency is shifted to the actual transmission frequency.

Hereinafter, a signal detection unit according to the present invention will be described in detail with reference to FIGS. 4 to 7.

4 is a configuration diagram of a signal detector according to an embodiment of the present invention. The signal detection unit may be implemented in various forms. The signal detection unit 140 ′ of FIG. 4 includes a magnitude calculator 144 ′, a comparator 146 ′, etc. This is an example of a signal detector that compares the magnitude with a threshold and determines that a signal has been detected when it is higher than the threshold.

The size calculator 144 ′ calculates the size of the digital signal output from the AD conversion unit 130. In addition, the comparator 146' compares the signal level calculated by the size calculator 144' with a preset threshold, and the result of signal detection (e.g., H(1) when a radio signal is detected, and the radio signal is not detected). In case L(0)) is transmitted to the controller 150.

In detail, when the input signal of the signal detection unit 140' is expressed as x(mT), x(mT) is a carrier wave (or an intermediate frequency in the case of a frequency shift in the receiving circuit unit) ω _C as shown in Equation 1 below. It becomes the sum of the demodulated signal component s(mT) and the noise component n(mT).

[Equation 1]

Since x(mT) is a real number modulated with a carrier wave or an intermediate frequency, complex demodulation is performed as shown in Equation 2 below to form a complex number consisting of a real part z _r (mT) and an imaginary part z _i (mT) in the baseband. It can be represented by z _c (mT).

[Equation 2]

z _c (mT) = z _r (mT) + jz _i (mT) = s _r (mT) + n _r (mT) + j{s _i (mT) + n _i (mT)}

Here, s _r (mT), s _i (mT), n _r (mT), and n _i (mT) are the real part of the signal component, the imaginary part of the signal component, and the real part of the noise component of the complex number z _c (mT), respectively. It represents the negative and the imaginary part of the noise component.

Meanwhile, the signal power P _S and the noise power P _N are represented by Equations 3 and 4 below, respectively.

[Equation 3]

P _S = s _r ² (mT) + s _i ² (mT)

[Equation 4]

P _N = E{n _r ² (mT) + n _i ² (mT)}

Here, E{} means an expectation value. As is well known, the real and imaginary parts of the thermal noise are mutually independent, and are random variables having a complex Gaussian distribution with a variance of P _N and a mean of 0.

The size calculator 144 ′ calculates the size Λ of the signal input to the signal detector 140 ′, which may be calculated as shown in Equation 5 below.

[Equation 5]

Here, the thermal noise power P _N may be used as a measured value, but the bandwidth of the channel selection unit 160, the noise figure (NF) of the receiving circuit unit 120, and the input of the receiving circuit unit 120 to the AD conversion unit 130 It can also be calculated using the amplification degree and the conversion factor of the AD conversion unit 130.

The comparator 146' is a threshold value determined according to the preset probability of false alarm P _FA and the probability of detection P _D of the magnitude of the input signal calculated by the magnitude calculator 144'. It compares with (threshold) η to determine the presence or absence of a radio signal, and transmits the result (signal detection result) to the control unit 150.

Specifically, when H ₁ is a hypothesis that determines that there is a signal, H ₀ is a hypothesis that determines that there is no signal, and the threshold is η, the hypothesis test can be expressed as Equation 6 below. .

[Equation 6]

Here, test statistics Λ is a random variable having a Rician distribution. And, the cumulative distribution function (CDF) of Λ is given in Equation 7 below.

[Equation 7]

CDF _Λ = 1-Q ₁ (ν,Λ)

Here, ν = (P _S /P _N ) ^1/2 = SNR ^1/2 , and Q ₁ (ν,Λ) is a Marcum-Q function.

And, Probability of False Alarm P _FA Is obtained from the complementary cumulative distribution function (CCDF) of _Λ , i.e. 1-CDF _Λ when ν = 0, and the probability of detection P _D is by using the CCDF of Λ when ν = SNR ^1/2 You can get it. Accordingly, the detection probability P _D and the false detection probability P _FA according to the SNR of the output of the variable gain amplifier for each input of the receiving circuit unit 120 are shown as ROC curves as shown in FIG. 5. Referring to FIG. 5, it can be seen that detection performance is improved as SNR increases to 0dB, 6dB, 12dB, 18dB, and 24dB.

On the other hand, Figure 6 shows a signal detection unit 140" using a plurality of narrow-band filters in another embodiment of the signal detection unit according to the present invention. And, Fig. 7 shows a plurality of signal detection units 140". It shows a method of detecting a signal using a narrowband filter.

6 and 7, the signal detection unit 140" includes a plurality of (N) narrowband filters 142"-1 to 142"-N, and a plurality of size calculators 144"-1 to 144. "-N), a plurality of comparators 146"-1 to 246"-N, a determiner 148", and the like.

When the bandwidth B _R of the receiving circuit unit 120 is, for example, 40 MHz, and channels used in the field, that is, channels to be relayed, are distributed in a bandwidth of, for example, 10 MHz (B _S = B _S1 + B _S2 ) (see FIG. 7A), The signal detection unit 140" divides this into N narrowband filters 142"-1 to 142"-N and filters them (see Fig. 7B). Narrowband filters 142"-1 to 142"-N) Is a filter whose pass bandwidth is narrower than that of the input signal, and is preferably implemented as an integer multiple of the channel frequency interval of the radio, but is not limited thereto.

N outputs that pass through each narrow-band filter (142"-1 to 142"-N) are input to each size calculator (144"-1 to 144"-N) to calculate their size, and calculate each size The outputs of the groups 144"-1 to 144"-N are input to the comparators 146"-1 to 146"-N, respectively, and are compared with a preset threshold. And, the result (detection result) of each comparator 146"-1 to 146"-N is input to the determiner 148", and the determiner 148" includes N comparators 146"-1 to 146 If it is determined that any one of the detection results of "-N) has a signal, it is determined that the signal is detected (see Fig. 7E).

A signal is input to one channel within the relay bandwidth, and the signal power is applied to each variable gain amplifier 126', 126" of the receiving circuit unit 120, that is, a variable gain amplifier 126' that amplifies the first input of the receiving circuit unit. When the output of the variable gain amplifier 126" that amplifies the second input of the receiving circuit unit has a signal-to-noise ratio (SNR) of 0 dB, the output of the receiving circuit unit 120 is two variable gain amplifiers ( 126', 126") Since the sum of the outputs, the thermal noise power is doubled and the signal-to-noise ratio becomes -3dB, that is, 1/2 (see Figs. 7C, 7D and 7E). However, the signal detection unit 140") N narrowband filters (142"-1 to 142"-N) are used only for the bandwidth to be relayed, so the total bandwidth to detect a signal is reduced to 1/4 from 40MHz to 10MHz in the reception circuit part, and again N narrowband filters Since it is reduced to 1/N, the SNR of the output signal of each narrow-band filter (142"-1 to 142"-N) increases N times more than the output of the reception circuit unit 120, and ν = [1/{2×( 40/10)×N)}] ^1/2 = (2×N) ^1/2 .

When a radio signal is received, it passes through one narrow-band filter, so if ν = (2×N) ^1/2 is substituted in Equation 7 above and the detection probability P _D of the signal is calculated from CCDF _Λ, that is, 1-CDF _Λ , Same as Equation 16.

[Equation 8]

P _D = 1- CDF _Λ = 1-Q ₁ ((2×N) ^1/2 ,Λ)

On the other hand, when there is no signal, it is falsely detected unless all of the N narrow-band filters determine that there is no signal, and each of the N narrow-band filters passes only different signal bands, so they are mutually independent and since there is no signal, ν is 0. , Substituting ν = 0 in Equation 7 above and multiplying the value N times to find the probability of determining that there is no signal in all N narrowband filters when there is no signal, and then subtracting the value from the total probability 1 when there is no signal The false detection probability P _FA for determining that there is a signal is as shown in Equation 9 below.

[Equation 9]

P _FA = 1- CDF _Λ ^N = 1- {1- Q ₁ (0,Λ)} ^N

Accordingly, when N is 1, 2, 4, 8, 16, 32, the detection probability P _D and the false detection probability P _FA are shown in ROC curves as shown in FIG. Referring to FIG. 8, as the number of narrowband filters used in the signal detection unit 140" increases, such as N = 2, 4, 8, 16, 32, as the bandwidth of each filter decreases, the detection performance is greatly improved. I can understand the feeling.

9 is a block diagram of a half-duplex wireless relay device according to a second embodiment of the present invention.

9, the half-duplex wireless repeater 200 according to the second embodiment of the present invention includes an antenna switching unit 210, a receiving circuit unit 220, an AD conversion unit 230, a signal detection unit 240, A control unit 250, a channel selection unit 260, a signal delay unit 270, a DA conversion unit 280, a transmission circuit unit 290, and the like are included.

The half-duplex wireless relay device 200 according to the second embodiment of the present invention shows a difference in that a channel selector is added compared to the half-duplex wireless relay device 100 according to the first embodiment described above, and the remaining components are substantially Is the same or similar. Therefore, in the following description, the features and differences of the second embodiment compared to the first embodiment will be mainly described, and the remaining contents may be referred to the first embodiment.

The channel selector 260 filters at least one pre-selected channel frequency with respect to the digital signal output from the AD converter 230.

In this regard, FIG. 10 is a configuration diagram of a channel selection unit according to an embodiment of the present invention. Referring to FIG. 10, the channel selector 260 according to an embodiment of the present invention includes a digital filter 262 and a scaler 264.

The digital filter 262 selects and filters only a pre-selected channel frequency (eg, a channel frequency actually used in the field) for the digital signal output from the AD conversion unit 230. In addition, the scaler 264 up-scales the digital signal filtered by the digital filter 262 to a preset level.

In detail, when it is assumed that two signals of r ₁ (t) and r ₂ (t) having different channel frequencies are input from the receiving circuit unit 220 in phase, the AD conversion unit 230 samples them with a time period of T. The maximum size of the (sampling) and AD-converted signal |x ₀ (mT)|max is the AD converter output component |r ₁ (mT) of r ₁ (t) as shown in Equation 10 below, since the AD converter has linear characteristics. )|max and the output component of the AD converter of r ₂ (t) |r ₂ (mT)|max.

[Equation 10]

|x ₀ (mT)|max = |r ₁ (mT)|max + |r ₂ (mT)|max

If that of the channel selection section 260 to only relay r ₁ (t) component, the digital filter 262 is passed through a ₁ r (mT) and mainly components r ₂ (mT) component is suppressed. The digital filter 262 can adjust the amplification of the passband signal and the suppression of the signal other than the passband. By suppressing r ₂ (mT), the maximum size is Δ(Δ << |r ₂ (mT)|max ), the output x ₁ (mT) of the digital filter 262 becomes as in Equation 11 below.

[Equation 11]

|x ₁ (mT)|max = |r ₁ (mT)|max + Δ <|x ₀ (mT)|max

는 k를 넘지 않는 최대 정수를 의미한다.As a result, the maximum size of the output signal of the digital filter 262 is smaller than that of the input signal. For example, the maximum amplitude of r ₁ (t) is 0.5 Vp (Vp is the peak value), the maximum amplitude of r ₂ (t) is 0.5 Vp, and the maximum input range of the 16-bit AD converter is -1.0 V to 1.0 V. The conversion factor (that is, the conversion result value when converting 1.0V input to AD) is 2 ¹⁵ -1, the input range of the 16bit DA converter is -2 ¹⁵ ~ 2 ¹⁵ -1, and the output range accordingly is -1.0V ~ When the suppression degree for r ₂ (mT) is 1.0 V and 40 dB (0.01 times), the maximum values of the input and output of the digital filter 262 are as shown in Equations 12 and 13 below, respectively. For reference, in Equations 10 and 11 below

Means the maximum integer not exceeding k.

[Equation 12]

[Equation 13]

Further, the scaler 264 up-scales the output of the digital filter 262 to a preset level. For example, in the case of a 16-bit DA converter with an input range of -2 ¹⁵ to 2 ¹⁵ -1 as described above, the scaler 164 converts |x ₁ (mT)|max (=16547) to |x ₀ (mT)|max The dynamic range of the digital signal transmitted to the DA conversion unit 180 is expanded by upscaling 1.9802 times to the (=2 ¹⁵ -1) level.

)까지 출력할 수 있다. 이러한 동적영역이 확대되는 이점은 DA 변환부(280)의 출력을 처리하는 송신 회로부(290)로부터 무전기의 수신부에 이르기까지 영향을 미쳐 성능을 향상시킨다. 또한, 채널 선택부(260)를 거친 신호는 신호 대 잡음비(SNR; Signal-to-Noise Ratio)도 향상되어 신호 품질을 향상시킬 수 있으며, 따라서 도 9에서 신호 탐지부(240)가 AD 변환부(230)의 출력신호 대신에 채널 선택부(260)의 출력신호를 입력받으면 신호 탐지부(250)의 탐지 성능도 향상시킬 수 있다.Therefore, when channel selection is not performed, the r ₁ (t) component can be output only 0.5 Vp due to the limitation of the dynamic range of the DA converter, but in the present invention, the output of the signal to be relayed by using the channel selection unit 160 is 1.9802. By upscaling the r ₁ (t) component to 0.9901V (

) Can be printed. The advantage of expanding the dynamic range affects from the transmission circuit unit 290 processing the output of the DA conversion unit 280 to the reception unit of the radio, thereby improving performance. In addition, the signal passing through the channel selection unit 260 can also improve the signal-to-noise ratio (SNR) to improve the signal quality. Accordingly, the signal detection unit 240 in FIG. When the output signal of the channel selection unit 260 is input instead of the output signal of 230, the detection performance of the signal detection unit 250 may be improved.

11 is a block diagram of a half-duplex wireless relay apparatus according to a third embodiment of the present invention.

Referring to FIG. 11, a half-duplex wireless repeater 300 according to a third embodiment of the present invention includes an antenna switching unit 310, first and second receiving circuit units 320', 320', and first and second receivers. AD conversion unit 330', 330", signal selection unit 340a, signal detection unit 340, control unit 350, signal delay unit 370, DA conversion unit 380, transmission circuit unit 390, etc. Includes.

The half-duplex wireless relay device 300 according to the third embodiment of the present invention is provided with a plurality of reception circuit units and AD conversion units compared to the half-duplex wireless relay device 100 according to the first embodiment, and a signal selector is added accordingly. There is a difference in that, and the rest of the configurations are substantially the same or similar. Therefore, in the following description, the features and differences of the third embodiment compared to the first embodiment will be mainly described, and the remaining contents may be referred to the first embodiment.

The half-duplex wireless relay device 300 according to the third embodiment of the present invention includes a plurality of receiving circuit units 320 ′ and 320 ″ and AD conversion units 330 ′ and 330 ″ and transmitted from the antenna switching unit 310. The signals are processed in a plurality of paths, and are preferably processed for each path according to the number of antennas 301 and 302.

For example, a signal received from the first antenna 301 is filtered and amplified by the first receiving circuit unit 320 ′, and then converted into a digital signal by the first AD conversion unit 330 ′, and then transferred from the second antenna 302. The received signal is filtered and amplified by the second receiving circuit unit 320" and then converted into a digital signal by the second AD conversion unit 330". Further, the digital signal output from the first AD conversion unit 330' and the digital signal output from the second AD conversion unit 330 ″ are transmitted to the signal selection unit 340a, respectively, and are added together to form a signal delay unit ( 370).

In the standby state, the control unit 350 controls the signal selection unit 340a to sequentially select the output signals of the first and second AD conversion units 330 ′ and 330 ″, and accordingly, the signal detection unit 340 Detects the presence or absence of a radio signal for each output signal of the first and second AD conversion units 330 ′ and 330 ″ which are sequentially selected and input from the signal selection unit 340a, and controls the result (signal detection result) Send to 350. The control unit 350 determines the presence or absence of a radio signal based on the signal detection result transmitted from the signal detection unit 340, and if there is a radio signal, it can know through which antenna the radio signal is received. The antenna switching unit 310 is controlled to set a reception path for an antenna receiving a signal and a transmission path for the other antennas.

For reference, since the half-duplex wireless repeater 300 according to the third embodiment of the present invention detects a radio signal by separating each signal received through a plurality of antennas, the signal input to the signal detection unit 340 is Since the signal-to-noise ratio (SNR) does not deteriorate, there is an advantage in that detection performance is improved compared to the first and second embodiments described above. That is, in the first and second embodiments, noise components of all antenna signals are added together, so the noise power increases by the number of antenna signals, whereas in the third embodiment, each antenna signal is processed, so that the signal-to-noise ratio is reduced to a single antenna signal. Same as in the case of

12 is a block diagram of a half-duplex wireless relay apparatus according to a fourth embodiment of the present invention.

Referring to FIG. 12, a half-duplex wireless repeater 400 according to a fourth embodiment of the present invention includes an antenna switching unit 410, first and second receiving circuit units 420', 420', and first and second receivers. AD conversion units 430', 430', first and second signal selection units 440a and 440b, signal detection unit 440, control unit 450, first and second signal delay units 470', 470 &Quot;), a DA conversion unit 480, a transmission circuit unit 490, and the like.

The half-duplex wireless relay device 400 according to the fourth embodiment of the present invention is provided with a plurality of signal delay units compared to the half-duplex wireless relay device 300 according to the third embodiment described above, and a second signal selector is added accordingly. There is a difference in points, and the rest of the configurations are substantially the same or similar. Therefore, in the following description, the features and differences of the fourth embodiment compared to the third embodiment will be mainly described, and the first to third embodiments may be referred to for the rest.

The half-duplex wireless relay device 400 according to the fourth embodiment of the present invention includes a plurality of receiving circuit units 420 ′ and 420 ″ and AD conversion units 430 ′ and 430 ″ as in the third exemplary embodiment, and signal delay A plurality of units 470 ′ and 470 ″ are also provided to process signals transmitted from the antenna switching unit 410 into a plurality of paths.

For example, a signal received from the first antenna 401 is filtered and amplified by the first receiving circuit unit 420 ′, and then converted into a digital signal by the first AD converter 430 ′, and the first signal delay unit 470 ′ ) Is delayed for a certain period of time, and likewise, the signal received from the second antenna 402 is filtered and amplified by the second receiving circuit unit 420", and then converted into a digital signal by the second AD converter 430". 2 The digital signal output from the first signal delay unit 470 ′ and the digital signal output from the second signal delay unit 470 ″ are respectively delayed by the signal delay unit 470". It is transmitted to the signal selection unit 440b.

Meanwhile, as in the third embodiment, the control unit 450 controls the signal selection unit 440a to sequentially select the output signals of the first and second AD conversion units 430 ′ and 430 ″, and the signal detection unit ( 440), and after classifying the antenna that is currently receiving the radio signal based on the signal detection result of the signal detection unit 440, the second signal selection unit 440b so that the signal of the corresponding antenna can be transmitted. That is, the second signal selection unit 440b is controlled to select a signal having a radio signal among the output signals of the first and second signal delay units 470' and 470'.

For reference, since the half-duplex wireless repeater 400 according to the fourth embodiment of the present invention does not combine and transmit a plurality of antenna signals, the signal-to-noise ratio of the transmitted signal is not deteriorated. Likewise, compared to the first and second embodiments, the detection performance is improved, and the quality of the transmitted signal is improved compared to the third embodiment.

13 is a block diagram of a half-duplex wireless relay apparatus according to a fifth embodiment of the present invention.

13, a half-duplex wireless repeater 500 according to a fifth embodiment of the present invention includes an antenna switching unit 510, a receiving circuit unit 520, an AD conversion unit 530, a signal detection unit 540, A control unit 550, a channel selection unit 560, a signal delay unit 570, a DA conversion unit 580, a transmission circuit unit 590, and the like are included.

In the half-duplex wireless relay device 500 according to the fifth embodiment of the present invention, the function of the receiving circuit unit is slightly added compared to the half-duplex wireless relay device 100 according to the first embodiment described above, and a channel selection is performed after the signal delay unit. It shows a difference in the point of having additional parts, and the rest of the configurations are substantially the same or similar. Therefore, in the following description, the features and differences of the fifth embodiment compared to the first embodiment will be mainly described, and the remaining contents may be referred to the first embodiment.

14 is a block diagram of a receiving circuit unit according to another embodiment of the present invention. The half-duplex wireless relay device 500 according to the fifth embodiment of the present invention includes a plurality of frequency modulators 528' and 528' in the receiving circuit unit 520 as shown in FIG. 14, and the receiving circuit unit 520 Each signal (refer to Figs. 15A and 15B) transferred to a plurality of inputs of) is transferred to different frequency bands using different modulation frequencies and then summed and output (refer to Fig. 15C). By receiving a plurality of analog signals from the antenna switching unit 510, each of the low noise amplifiers 522', 522", bandpass filters 524', 524", and variable gain amplifiers 526', 526" After modulating by frequency, these signals are summed and output through one path.

The AD conversion unit 530 converts the analog signal output from the reception circuit unit 520 into a digital signal, and the digital signal output from the AD conversion unit 530 is input to the signal delay unit 570. In addition, the signal delay unit 570 delays a digital signal including all of the plurality of intermediate frequency bands for a predetermined time, and then transmits the digital signal to the channel selection unit 560.

The signal detection unit 540 determines whether there is a signal (radio signal) to be relayed for each of a plurality of intermediate frequency bands included in the digital signal output from the AD conversion unit 530, and the result (signal detection result) Is transmitted to the control unit 550.

The control unit 550 determines the presence or absence of a radio signal based on the signal detection result transmitted from the signal detection unit 540, and if there is a radio signal, the control unit 550 sets a reception path for the antenna currently receiving the radio signal, and Controls the antenna switching unit 510 to set a transmission path for the other antennas, and also controls the channel selector 560 to select only the signal band to be relayed in the intermediate frequency band including the antenna signal from which the radio signal is detected. Thus, it is output to the DA conversion unit 580 (see FIG. 15D). In this case, the DA conversion unit 580 makes the transition to a predetermined intermediate frequency band, for example, the first intermediate frequency band, regardless of which one of the plurality of intermediate frequency bands is selected (see FIG. 15E), and the transmission circuit unit 590 is always The first intermediate frequency band is shifted to the original band, so that the complexity of the transmission circuit unit 590 is not increased even if the number of intermediate frequency bands is large (see FIG. 15F).

For reference, in the half-duplex wireless repeater 500 according to the fifth embodiment of the present invention, since a plurality of antenna signals band-filtered by the receiving circuit unit 520 are divided into different intermediate frequency bands and then combined, Noise does not increase. Therefore, the performance of the signal detection unit 540 that sequentially attempts to detect whether there is a signal (radio signal) to be relayed for each intermediate frequency band has the same performance as in the third and fourth embodiments described above, and channel selection Since the unit 560 also selects a band to be relayed within one intermediate frequency band, the signal-to-noise ratio of the transmitted signal is not deteriorated, and thus the quality of the transmitted signal is improved as in the fourth embodiment.

16 is a block diagram of a half-duplex wireless relay apparatus according to a sixth embodiment of the present invention.

Referring to FIG. 16, the half-duplex wireless repeater 600 according to the sixth embodiment of the present invention includes an antenna switching unit 610, a receiving circuit unit 620, an AD converter 630, and first and second signal selection. Units 640a and 640b, signal detection unit 640, control unit 650, first and second channel selection units 660 ′ and 660 ″, first and second signal delay units 670 ′ and 670 ″ , A DA conversion unit 680, a transmission circuit unit 690, and the like.

The half-duplex wireless relay device 600 according to the sixth embodiment of the present invention, as in the fifth embodiment, includes a plurality of frequency modulators in the receiving circuit unit 620 and each transmitted to a plurality of inputs of the receiving circuit unit 620 The signals of are shifted to different frequency bands using different modulation frequencies, are then summed and output, and the AD conversion unit 630 converts the analog signal output from the receiving circuit unit 620 into a digital signal.

The digital signal output from the AD conversion unit 630 is a first antenna that is shifted from the receiving circuit unit 620 to the first intermediate frequency band through the first channel selection unit 660' and the second channel selection unit 660″. Among the signal and the second antenna signal shifted to the second intermediate frequency band, only a band including a channel to be relayed is selected and output, and the output of the first channel selector 660' is output from the first signal delay unit 670'. ) And the output of the second channel selection unit 660" is input to the second signal delay unit 670", and thereafter, the process is performed in the same or similar process as in the fourth embodiment.

Finally, FIG. 17 shows a burst signal processing method of a digital radio in the half-duplex wireless relay device according to the present invention.

Radios that have been widely used in the past are voice-only communication devices of the FM modulation method, but in recent years, voice and data communication devices of the digital modulation method are rapidly being introduced. In the digital modulation method, information such as voice, video, and text is encoded and transmitted in block units after processing such as frequency modulation. A transmission switch, that is, a hook signal is generated and a meaningful audio signal is transmitted. Unlike the conventional analog method, which has a spare time, when transmission starts, information of each block unit is immediately transmitted in the form of a burst (see FIG. 17A). Therefore, there is a problem in that the loss of the received signal is inevitable during the time when the half-duplex wireless relay device detects a signal (digital signal) and switches from transmission to reception or reception to transmission (see FIGS. 17B and 17C). However, since the present invention delays transmission until a correct transmission/reception path is established for a plurality of antennas by having a signal delay unit, it is possible to relay without waveforms and/or information lost from the received signal. It is very useful for a digital type radio that transmits information to the radio (see Fig. 17D).

Although the present invention has been described in detail with reference to preferred embodiments so far, those skilled in the art to which the present invention pertains can be implemented in various other specific forms without changing the technical spirit or essential features of the present invention. The embodiments are illustrative in all respects and should be understood as non-limiting.

And, the scope of the present invention is specified by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. Should be interpreted as.

Claims (10)

delete As a half-duplex wireless relay device,
An antenna switching unit for setting a transmission path or a reception path for the first and second antennas, respectively;
A receiving circuit unit configured to amplify at least one of the first and second analog signals with a first amplification degree by receiving the first analog signal received through the first antenna and the second analog signal received through the second antenna;
An AD converter for converting the at least one amplified first and second analog signals into digital signals;
A signal delay unit delaying the converted digital signal for a preset delay time;
A DA conversion unit converting the delayed digital signal into an analog signal;
A transmission circuit unit for transmitting the converted analog signal to the antenna switching unit;
A signal detection unit detecting whether there is a radio signal from the converted digital signal; And
When the radio signal is detected by the signal detection unit, the first amplification level is adjusted to determine a signal including the radio signal among the first and second analog signals, and a reception path is set for an antenna receiving the radio signal. And a control unit for controlling the antenna switching unit to set a transmission path for an antenna that does not receive the radio signal. The method of claim 2,
The receiving circuit unit amplifies the first analog signal with a first amplification degree and amplifies the second analog signal with a second amplification degree,
The control unit determines a signal including a radio signal among the first and second analog signals by sequentially adjusting the first amplification degree and the second amplification degree when the radio signal is detected by the signal detection unit. Wireless relay device. The method according to claim 2 or 3,
And a channel selector configured to filter at least one pre-selected channel frequency for the digital signal and upscale the filtered digital signal to a preset level. As a half-duplex wireless relay device,
An antenna switching unit for setting a transmission path or a reception path for the first and second antennas, respectively;
A first receiving circuit unit for receiving a first analog signal through the first antenna and a second receiving circuit unit for receiving a second analog signal through the second antenna;
A first AD conversion unit for converting a first analog signal output from the first receiving circuit unit into a first digital signal and a second AD conversion unit for converting a second analog signal output from the second receiving circuit unit into a second digital signal part;
A signal delay unit delaying the first and second digital signals output from the first and second AD conversion units for a preset delay time;
A DA conversion unit converting the digital signal output from the signal delay unit into an analog signal;
A transmission circuit unit for transmitting the converted analog signal to the antenna switching unit;
A first signal selection unit selecting one of the first and second digital signals output from the first and second AD conversion units;
A signal detection unit detecting whether there is a radio signal from the digital signal selected by the signal selection unit; And
When the radio signal is detected by the signal detection unit by controlling the first signal selection unit, the antenna sets a receiving path for an antenna receiving the radio signal and a transmission path for an antenna not receiving the radio signal. Half-duplex wireless relay device comprising a control unit for controlling the switching unit. The method of claim 5,
The signal delay unit may include a first signal delay unit delaying the first digital signal output from the first AD conversion unit for a preset delay time and the second digital signal output from the second AD conversion unit. Including a second signal delay unit for delaying for a delay time,
And a second signal selection unit for selecting one of the first and second digital signals output from the first and second signal delay units and transmitting them to the DA conversion unit. delete As a half-duplex wireless relay method,
Receiving a first analog signal through a first antenna and a second analog signal through a second antenna;
Amplifying at least one of the first and second analog signals with a first amplification degree;
Converting the at least one amplified first and second analog signals into digital signals;
Delaying the converted digital signal for a preset delay time and adjusting the first amplification degree to determine an antenna for receiving a radio signal from among the first and second antennas;
Converting the delayed digital signal into an analog signal; And
And transmitting the converted analog signal through an antenna that does not receive a radio signal among the first and second antennas. The method of claim 8,
The amplifying step amplifies the first analog signal with a first amplification degree and amplifies the second analog signal with a second amplification degree,
The determining step comprises determining an antenna for receiving a radio signal from among the first and second antennas by adjusting the first and second amplification degrees. delete

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