KR100414077B1 - Receiver of mobile communication system - Google Patents

Abstract

The present invention relates to a receiver of a mobile communication system, and in particular, to receive two bandwidths using a duplexer to process a digital signal, unlike an analog case, so that a separate tuning is not required and the error can be reduced. To a receiver. To this end, the present invention provides a receiver having a redundant structure, comprising: a low noise amplifier for low noise amplifying and outputting a high frequency signal received through a receiving antenna; A frequency down part for dividing a band of an output signal of the low noise amplifier and then down-regulating a frequency; An analog / digital converter unit for converting an analog output signal of the frequency downlink unit into a digital unit and synchronizing with a clock signal to output a digital signal; An automatic gain adjustment circuit for dividing the channels of the digital signal to down-regulate the frequency of each channel, reducing the bandwidth and filtering the gain at the same time; It characterized in that the monitor is configured to monitor the output signal of the automatic gain adjustment circuit to determine whether there is an error.

Description

Receiver of mobile communication system {RECEIVER OF MOBILE COMMUNICATION SYSTEM}

The present invention relates to a receiver of a mobile communication system, and in particular, to receive two bandwidths using a duplexer to process a digital signal, unlike an analog case, so that a separate tuning is not required and the error can be reduced. To a receiver.

In general, the conventional method is a method of selecting and receiving the most optimal state of the received signal without distortion of the signal received through the two receiving antennas, the signal input by the double conversion method, such a conventional technique When described with reference to the accompanying drawings as follows.

FIG. 1 is an exemplary view showing a configuration of a receiver of a conventional mobile communication system. As shown in FIG. 1, in a redundant receiver, amplified high frequency signals received from the first and second receiving antennas 18 and 19 are illustrated in FIG. A front end portion 11 for removing the out-of-band signal; A first gain control unit 13 or 14 for adjusting a gain of a signal passing only a band of a desired signal by mixing the output signal of the front end portions 11 and 12 and the output signal of the first local frequency generator 80; ; A second gain adjusting unit (15, 16) for adjusting a gain of a signal passing only a predetermined band among the output signals of the gain adjusting unit; It is composed of an automatic gain adjusting unit 17 which receives the output transmission signals of the second gain adjusting units 15 and 16 and adjusts the transmission signals to the baseband and adjusts the gain.

The automatic gain adjusting unit 17 includes a test unit 17a for checking a path connection of an input transmission signal; First and second baseband converters 17c and 17d for receiving an input signal from the test unit 17a and down-adjusting it to a baseband signal to remove an image signal and widen the signal band; A monitor 17e for monitoring the signals of the first and second baseband converters 17c and 17d is described below.

The first and second low noise amplifiers 11a and 12a amplify the low noise signal among the high frequency signals received through the first reception path A PATH and the second reception path B PATH of the redundant reception structure.

The output signals of the first and second low noise amplifiers 11a and 12a are amplified through the first and second variable voltage amplifiers 11b and 12b and input to the first and second bandpass filters 11c and 12c. Pass only a certain band.

The output signals of the first and second band pass filters 11c and 12c and the output signals of the first and second local frequency generators 80 and 90 are input to the first and second mixers 13a and 14a and mixed. do. At this time, the first and second amplifiers 13b and 14b compensate for the loss of the mixed signal, and the outputs of the first and second amplifiers 13b and 14b are the first and second small filter SAW Fiters 13c. , 14c) passes only the band of the desired signal and removes the signal outside the band. At this time, the signal processes only 1FA band.

Third and fourth sub-filters 13e and 14e and first to third amplifying and filtering to adjust gains of the output signals of the first and second sub-filters 13c and 14c output through the above process. Compare the signal output through the voltage gain amplifiers 13d, 13f, 13h, 14d, 14f, and 14h with the reference voltage and then adjust the signals of the error adjusting units 13j and 14j to adjust the error so that the first to third voltages are adjusted. The gain is adjusted by returning to the gain amplifiers 13d, 13f, 13h, 14d, 14f, and 14h.

As a result, the gain-adjusted signal is output to the error adjusting units 13j and 14j and the second gain adjusting units 15 and 16 through the dividers 13i and 14i.

The second gain adjusting unit 15, 16 receives a signal filtered through the third and fourth band pass filters 15a and 16a and a signal obtained by automatically adjusting the gain of the automatic gain adjusting unit 17 to adjust the gain. Output to the gain adjusting unit 17.

Accordingly, the automatic gain adjusting unit 17 uses the first and second baseband converting units 17c and 17c through a test unit 17a for self-testing the path connection of the output signals of the second gain adjusting units 15 and 16. 17d) outputs the output signals of the second gain adjusting units 15, 16.

As a result, the first and second baseband converters 15 and 16 output the Numerically Controlled Oscillator 102N to the first and second mixers 100a, 100b, 101a, and 101b. And outputs the I and Q channel signals after inputting and mixing the output signals of the second gain adjusting units 15 and 16 together with the signal, wherein the image signal removing unit IRF removes the image signal generated by the above process. Determining and diagnosing by finally monitoring whether the received signal has an error through an interpolation unit (IP) 104a to 104d that widens the bandwidth of a signal that is the rate of the weakened signal through 103a to 103d. Output to the reception signal monitor 17e.

The monitor 17e formats the received signal by selecting the received signal in the most optimal state without being distorted among the signals received through the above process.

However, the conventional receiver operating as described above uses many components because it requires high gain, and in particular, due to the large size of the expensive small filter, there are economic problems with limitations in achieving miniaturization of the receiver, Due to the large loss due to the small filter, there is a problem in that a plurality of amplifiers are used.

Accordingly, the present invention has been made to solve the above problems, and unlike conventional analog receivers, it is possible to significantly reduce the elements of the intermediate frequency, and to process the digital signal by receiving two bandwidths using a duplexer. Unlike analog, no additional tuning is required and errors can be reduced.

In addition, by optimally designing a receiver and a digital filter capable of processing two bands, the object of the present invention is to provide a receiver of a compact mobile communication system by making several boards into one sheet.

1 is an exemplary view showing the configuration of a receiver of a conventional mobile communication system.

2 is an exemplary view showing a configuration of a receiver of a mobile communication system of the present invention.

Figure 3 is an exemplary view showing another embodiment of the receiver of the present invention mobile communication system.

*** Explanation of symbols for main parts of drawing ***

21, 22: first and second low noise amplifiers 23, 24: first and second duplexers

25, 26: 1st, 2nd mixing part 25a, 26a: 1st mixer

25b, 26b: second mixer 27a, 27b: first phase synchronizer

28 and 29: first and second intermediate frequency filter units 30 and 31: analog / digital converter units

32, 33: monitor 34, 35: first and second receiving antenna

40: frequency down part 50: automatic gain adjustment circuit

51a to 51d: Encio 52a to 52d: CIC filter

53a to 53d: first FIR filter 54a to 54d: second FIR filter

55a to 55d: automatic gain adjusting unit 61a to 61d: first to fourth mixers

62a to 62d: fifth to eighth mixers 63a to 63d: multiplexer

According to an aspect of the present invention, there is provided a receiver having a redundant structure for receiving a redundant band, comprising: a low noise amplifier for low noise amplifying and outputting a high frequency signal received through a receiving antenna; A frequency down part for dividing a band of an output signal of the low noise amplifier and then down-regulating a frequency; An analog / digital converter unit for converting an analog output signal of the frequency downlink unit into a digital unit and synchronizing with a clock signal to output a digital signal; An automatic gain adjustment circuit for dividing the channels of the digital signal to down-regulate the frequency of each channel, reducing the bandwidth and filtering the gain at the same time; It characterized in that the monitor is configured to monitor the output signal of the automatic gain adjustment circuit to determine whether there is an error.

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

2 is an exemplary view showing a configuration of a receiver of a mobile communication system according to the present invention. As shown in FIG. 2, in a receiver having a redundant band structure, a low noise amplifier for low noise amplifying and outputting a high frequency signal received through a receiving antenna is shown. (21, 22); A frequency down part 40 for dividing a band of an output signal of the low noise amplifiers 21 and 22 and then down-regulating the frequency; An analog / digital converter (30, 31) for converting the analog output signal of the frequency downlink part (40) into digital to output a digital signal in synchronization with a clock signal; An automatic gain adjustment circuit (50) for dividing channels of the digital signal to down-regulate the frequency of each channel, reducing the bandwidth, and filtering the gain at the same time; The monitor 32 and 33 are configured to monitor the output signal of the automatic gain adjustment circuit 50 to determine whether there is an error. The operation and operation of the present invention configured as described above will be described below.

First, the present invention receives frequencies of a dual band (DCN, IMT-2000) signal input through the first and second receiving antennas 34 and 35, and the signals are first and second low noise amplifiers having a wide bandwidth. LNA) (21, 22) to amplify.

The amplified signal is inputted to the first and second duplexers 23 and 24, filtered, and the band is separated by the filtering, and then passed to the first and second mixing units 25 and 26 of the next stage. Is output.

The separated band is divided into a DCN band having 824-849 MHz and an IMT-2000 band having a 1920-1980 MHz band.

The separated band signal includes the first and second mixers 25a and 26a of the first and second mixers 25 and 26 together with the output signals of the first and second phase synchronizers 27a and 27b. 25b and 26b are mixed to adjust the frequency downward and output the first and second intermediate frequency filter units IF filters 28 and 29.

In this case, the first and second IF filters 28 and 29 may respectively accommodate the first and second IF filters 28a, 29a, 28b, and 29b to accommodate 4FA. Select the band of.

There is a difference in bandwidth depending on the used bands of the first and second IF filters 28a, 29a, 28b, and 29b. The IMT-2000 has a bandwidth of 5 MHz * 4 and a DCN of 1.23 * 4 MHz. It should be designed to have a band of.

The two band-limited signals are converted to digital through an analog-to-digital converter (ADC).

In this case, since the signals of the dual band are four-carrier signals, an analog / digital converter (ADC) having a high speed and a high conversion is required to process these signals.

To this end, in the present invention, the first and second analog / digital converters 30a, 30b, and 80b in the receive paths A and B PATH using the analog / digital converters 30 and 31, which enable conversion of 80MSPS and 14bit. 31a, 30b, and 31b process the bands of the DCN and IMT-2000.

The signals digitally converted by the first and second analog / digital converters 30a, 31a, 30b, and 31b are synchronized by the first and second clocks CLOCK 1 and CLOCK 2 to output data.

The digitized signal is subjected to a Numerically Controlled Oscillator (NCO) (NCO 1 to NCO 8) to make a DC (frequency '0') signal to determine each channel.

As a result, the output signals of the encios 51a to 51d are reduced by a sampling integrator comb (CIC) filter 52a to 52d designed to use the signal bands of the DCN and IMT-2000. .

However, in order to prevent unwanted signals from entering during the process, the first FIR filters 53a and 53c appropriately reduce the band and make the desired signal band (1.23MHz / 2) very sharp. The number of taps of the filter is increased to increase the number of taps and to reduce the band appropriately through the second FIR filters 53b and 53d and to make the desired signal band (3.84 MHz / 2) very sharp. Increase.

As a result, the output signals for each channel are input to the automatic gain adjustment circuit 50 through the above process, and the gain is adjusted to have a constant output to monitor the monitors 32 and 33 of each of the receive paths A and B PATH. Determine and diagnose the error of the received signal.

Another embodiment of the present invention, which complements the analog / digital converter unit (ADC) 30, 31 of the embodiment shown in FIG. 2 of the present invention, is shown in FIG. A plurality of paths of the DCN and IMT-2000 are operated to operate even when a high range signal is output among the output signals of the first and second IF filters 28 and 29 of the A and B paths. Two analog / digital converters 61a to 62d, the second, fourth, sixth, and seventh analog / digital converters (ADCs) 61b, 61d, 62b, and 62d normally operate in a low signal region to provide a multiplexer ( 63a to 63d, and in the high signal region, the plurality of analog / digital converters (ADCs) 61a to 62d are simultaneously operated and mixed to output stable signals through the multiplexer (MUX) 63a to 63d. do.

In this case, as shown in FIG. 2, the signal is synchronized with the first and second clock signals CLOCK 1 and CLOCK 2.

As described in detail above, the present invention can significantly reduce an intermediate frequency element, and process two signals by receiving two bandwidths using a duplexer, so that unlike an analog case, no additional tuning is required and error is reduced. Can be.

In addition, by optimally designing a receiver and a digital filter that can handle two bands, it is possible to reduce the size by making several boards into one sheet.

Claims (8)

A receiver having a redundant structure, the receiver comprising: a low noise amplifier for low noise amplifying and outputting a high frequency signal input through a receiving antenna; A frequency down part for dividing a band of an output signal of the low noise amplifier and then down-regulating a frequency; An analog / digital converter unit for converting and outputting an analog output signal of the frequency downlink unit to digital; An automatic gain adjustment circuit for dividing the channels of the digital signal to down-regulate the frequency of each channel, reducing the bandwidth and filtering the gain at the same time; And a monitor configured to monitor an output signal of the automatic gain adjustment circuit to determine whether there is an error. 2. The apparatus of claim 1, wherein the frequency downlink unit comprises: first and second duplexers for filtering the input signal and dividing the received signal into first and second reception bands; First and second phase synchronizers for outputting signals for synchronizing phases of the output signals of the first and second duplexers; First and second mixing units for mixing the output signals of the first and second duplexers with the output signals of the first and second phase synchronization units to output a frequency signal adjusted downward; And a first and a second intermediate frequency filter unit configured to pass only the intermediate frequency band among the downlinked first and second reception band signals and output the same. The receiver of claim 1, wherein the analog / digital converter unit comprises an analog / digital converter configured to output a digital signal in synchronization with a clock signal. 2. The apparatus of claim 1, wherein the analog / digital converter comprises: first and second analog / digital converters for receiving a plurality of signals of the first and second reception bands and synchronizing with a clock signal to output a digital signal; And a multiplexer configured to output an output signal of the analog / digital converter according to the output signal of the analog / digital converter. The receiver of claim 4, wherein the first analog-to-digital converter is configured to output a digital signal by operating in a low signal region. The receiver of claim 4, wherein the second analog-to-digital converter is configured to operate in a high signal region and output a digital signal. 5. The multiplexer of claim 4, wherein the multiplexer selects and outputs an output signal of the first analog-to-digital converter in a low signal region at a normal low potential level, and the first and second analog / digital signals in a high signal region at a high potential level. Receiver of a mobile communication system, characterized in that configured to output the mixed output signal of the converter. 2. The apparatus of claim 1, wherein the automatic gain adjustment circuit comprises: an NSI for outputting a first reception band signal and a second reception band signal by mixing a predetermined frequency band with a sampled signal to make a DC (frequency '0'); A CIC filter unit filtering the first and second reception band signals to reduce a sampling range; First and second FIR filters for filtering out undesired unwanted signals among the output signals of the CIC filter unit to appropriately reduce a band and remove distortion; And an automatic gain adjusting unit configured to adjust a gain of an output signal of the second FIR filter and always receive a constant signal.