KR19990073463A - Method and apparatus for sending signal in a base station - Google Patents

Abstract

Disclosed is a signal transmission method and apparatus of a base station capable of obtaining diversity effect by delaying a signal transmitted from a base station configuring a mobile communication network for a predetermined time so that the same signal can be continuously received at a terminal. It is. The divider, delay, and combiner are connected to the sector interface card or up-counter that constitutes the signal transmission device of the base station, and the transmission signal is divided into two transmission signals. The delayed transmission signal and the delayed transmission signal are synthesized. When the synthesized transmission signal is transmitted through the base station antenna, the non-time delayed transmission signal and the time delayed transmission signal are applied to the terminal, and thus the reception rate of the terminal is greatly improved by the improved time diversity effect.

Description

Method and apparatus for sending signal in base station {Method and apparatus for sending signal in a base station}

The present invention relates to a signal transmitter of a base station constituting a mobile communication network, and more particularly, a signal transmitted from a base station constituting a mobile communication network is delayed for a predetermined time and transmitted twice, thereby continuously receiving the same signal to a terminal. The present invention relates to a signal transmission method and apparatus of a base station that can achieve diversity effect.

In general, the base station and the terminal constituting the mobile communication network always transmits and receives a signal in real time, and how accurately the terminal receives a signal transmitted from the base station to the terminal side greatly influences the performance of the terminal.

There are numerous signals transmitted from the base station to the terminal. That is, since the antenna of the terminal is lower than the surrounding structure and the wavelength of the radio wave is much smaller than the size of the surrounding structure, the terminal receives signals passing through various propagation paths. At this time, since the radio waves received by the terminal are the sum of the radio wave reception strengths through the multipaths, the signal to noise ratio decreases and the code error rate is increased. This phenomenon is called multipath fading. In other words, the radio waves in the 800MHz ~ 2㎓ band, which are mainly used in mobile communication, reach far enough and are transmitted to the rear of the building to some extent. Is reflected in the building, etc., several passages of radio waves from the base station to the terminal of the mobile communication system are created. Therefore, if a multipath occurs, the desired radio wave arrives from various directions, but since the radio wave is a wave having phase and amplitude, signals arriving from each direction cause interference with each other. In particular, the radio wave reflected by the building and reaching the receiver such as the terminal arrives in time because it is turned around compared to the radio wave which has been reached directly. In a typical city, the arrival time difference between the direct wave and the reflected wave can be several tens of milliseconds.

As described above, due to the misalignment of the radio wave arrival time arriving at the receiver, two signals having different phases arrive at the antenna of the receiver, and when the phases coincide with each other, the signals become stronger, but when the phases are reversed, the signals become weaker. There is a marked increase in fading.

In this case, in order to alleviate the effects of fading, a terminal uses a reception method of synthesizing or changing a plurality of reception signals having different radio wave reception strengths or signal-to-noise ratios to obtain a single signal output. Usually, different wave propagation combines polarization, frequency and angle of incidence alone, but sometimes they are combined again. This is the case of a diversity system, which is a wireless communication device that allows a signal received by selection or combination from two or more similar radio waves to be obtained.

However, in order to effectively obtain the conventional diversity system, the same signal must be transmitted using two transmission antennas of the base station, and the cost burden increases greatly when the RF block is extended.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to delay the signal transmitted from the base station constituting the mobile communication network for a predetermined time and transmit the signal twice, so that the same signal is continuously transmitted to the terminal. The present invention provides a signal transmission method of a base station which can obtain a diversity effect by allowing reception to be performed.

Another object of the present invention is to provide a signal transmission apparatus of a base station suitable for performing the signal transmission method of the base station.

1 is a view schematically showing a signal transmission apparatus of a general base station.

2 is a diagram schematically showing a first embodiment of a signal transmission apparatus of a base station according to the present invention.

3 is a diagram schematically showing a second embodiment of a signal transmission apparatus of a base station according to the present invention.

4 is a diagram schematically showing a third embodiment of a signal transmission apparatus of a base station according to the present invention.

5 is a diagram schematically showing a fourth embodiment of a signal transmission apparatus of a base station according to the present invention.

6 is a view schematically showing a fifth embodiment of a signal transmission apparatus of a base station according to the present invention.

7 is a diagram illustrating a signal transmission method of a base station according to the present invention.

<Brief description of symbols for the main parts of the drawings>

10: base station controller 20: channel card

30: analog synthesis card 40: sector interface card

50: up-converter 52: combiner

60: upconverter 70: delay

71: first amplifier 72: first phase shifter

73: analog filter 74: intermediate frequency generator

75: first A / D converter 76: first control unit

77: first memory 78: first D / A converter

79: radio frequency generator 80: second phase shifter

81: second A / D converter 82: second control unit

83: second memory unit 84: the second D / A converter

85: third phase shifter 90: linear power amplifier

95: base station antenna

In order to achieve the above object, the present invention includes a first step of separating a CDMA analog signal, which is a transmission signal, into a first transmission signal and a second transmission signal through a divider; A second step of applying a first transmission signal of the two signals separated in the first step to a combiner for synthesizing the applied signal; A third step of applying a second transmission signal of the two signals separated in the first step to a delay unit and applying a delay to the combiner for a predetermined time; And it provides a signal transmission method of the base station comprising a fourth step of synthesizing the first transmission signal and the second transmission signal applied through the second step and the third step and output through the antenna.

The present invention also provides a base station controller for controlling the operation of the base station, a plurality of channel cards for generating I and Q signals from the signal applied from the base station controller, the plurality of channel cards An analog composite card for combining several I signals and Q signals into one I signal and a Q signal, a sector interface card for converting the I and Q signals applied from the analog synthesis card into an antenna area of a base station, and the sector interface card A base station transmitter comprising: an up-converter for converting a frequency applied from an upconverter, and a linear power amplifier for amplifying a magnitude of a frequency applied from the up-converter and outputting a transmission signal through a base station antenna. The next connection is made to send two The arcs of separation dividers; A delay for time-delaying one transmission signal applied from the divider for a predetermined time; Provided is a signal transmission apparatus of a base station comprising a combiner for combining one transmission signal applied from the divider and another transmission signal applied from a delay.

The delay may further include a first amplifier for amplifying a signal applied from the upconverter through a divider; A first phase shifter for changing a phase of a signal applied from the first amplifier; And an analog filter for filtering the signal applied from the first phase shifter to time-delay the signal for a predetermined set time and applying the signal to the combiner.

The delay may include an intermediate frequency generator for converting a signal, which is a radio frequency applied from an upconverter, into an intermediate frequency through a divider; A first A / D converter for converting an intermediate frequency applied from the intermediate frequency generator into a digital signal; A first control unit connected to the first A / D converter and configured to temporarily store and output a signal in a first memory unit; A first D / A converter converting a signal applied from the first controller into an analog signal; A radio frequency generator for converting an intermediate frequency applied from the first D / A converter into a radio frequency; And a second phase shifter for changing the phase applied from the radio frequency generator to the combiner.

The delay may further include: a second A / D converter for converting an intermediate frequency applied from a sector interface card through a divider into a digital signal; A second controller for temporarily storing and outputting a signal applied from the second A / D converter to a second memory unit; A second D / A converter converting a signal applied from the second controller into an analog signal; And a third phase shifter for changing a phase of a signal applied from the second D / A converter and applying it to a combiner.

Also, a 3D / A converter converting the first I signal synthesized with the I signals applied from the plurality of channel cards into an analog signal, and the first Q signal synthesized with the Q signals applied from the plurality of channel cards as the analog signal. 5D / A converter to convert, and a first synthesizer for synthesizing the first I signal applied from the 3D / A converter and the first Q signal applied from the 5D / A converter into one and outputting a first I + Q signal. The analog synthesis card may include: a third controller configured to temporarily store and output a first I signal synthesized with I signals applied from a plurality of channel cards to a third memory unit; A 4D / A converter for converting the second I signal delayed for a predetermined time through the third controller into an analog signal; A fourth control unit for temporarily storing and outputting a first Q signal obtained by combining Q signals applied from a plurality of channel cards to a fourth memory unit; A sixth D / A converter converting the second Q signal delayed for a predetermined time through the fourth controller into an analog signal; A delay comprising a second synthesis unit configured to synthesize a second I signal applied from the 4D / A converter and a second Q signal applied from the 6D / A converter into one and output a second I + Q signal; The first I + Q signal applied from the unit and the second I + Q signal applied from the second synthesis unit are combined together in the third synthesis unit and output to the sector interface card.

Hereinafter, a signal transmission apparatus of a base station according to the present invention will be described with reference to the accompanying drawings.

1 is a diagram schematically showing a signal transmission apparatus of a general base station, FIG. 2 is a diagram schematically showing a first embodiment of a signal transmission apparatus of a base station according to the present invention, and FIG. 3 is a signal of a base station according to the present invention. 4 is a diagram schematically showing a second embodiment of a transmission apparatus, and FIG. 4 is a diagram schematically showing a third embodiment of a signal transmission apparatus of a base station according to the present invention, and FIG. 5 is a signal transmission apparatus of a base station according to the present invention. Figure 4 schematically shows a fourth embodiment of the present invention, Figure 6 schematically shows a fifth embodiment of the signal transmission apparatus of the base station according to the present invention, Figure 7 shows a signal transmission method of the base station according to the present invention Drawing.

Hereinafter, the present invention will be described with reference to FIGS. 1 to 7.

First, as shown in Figure 1, the signal output from the base station controller (Base Station Controller) 10 for controlling the operation of the base station is applied to a plurality of channel cards (Channel) 20, the channel card 20 In the above, the I and Q signals are generated from the signal applied from the base station controller 10. The I and Q signals respectively output from the plurality of channel cards 20 are applied to an analog common card 30, and the analog synthesis card 30 is respectively from the plurality of channel cards 20. Multiple I signals and Q signals to be applied are combined into one I signal and Q signal. I and Q signals output from the analog synthesis card 30 are applied to a sector interface card 40, and the sector interface card 40 is an I signal applied from the analog synthesis card 30. And Q signal are converted into the antenna region of the base station. Since the frequency of the signal applied from the sector interface card 40 corresponds to the intermediate frequency of 4.95 MHz band, the up-converter 60 converts the radio frequency into 800 MHz to 1.8 GHz band. Since the magnitude (less than 1W) of the radio frequency applied from the up-converter 60 is very weak, it is amplified by a linear power amplifier 90 to smoothly output a signal through the base station antenna.

1 and 2, a divider 50 is connected to a sector interface card 40 for outputting an intermediate frequency signal or an up-converter 60 for outputting a radio frequency signal. ) Splits the transmission signal into two signals. One transmission signal among the transmission signals divided into two signals in the divider 50 is applied to the delay 70, and the delay 70 receives the transmission signal applied from the divider 50 for a predetermined time (1/8 chip). Is applied to the combiner 52 with a time delay for ˜1 / 2 chip). Accordingly, one of the two transmission signals separated from the divider 50 is directly applied to the combiner 52, and the other transmission signal is delayed for a predetermined time in the delay, and then the combiner 52 Is applied. The combiner 52 combines one transmission signal applied from the divider 50 and the other transmission signal applied from the delay 70 and transmits it through the base station antenna 95.

The 1 chip corresponds to 1 / 1.2288 MHz.

1 to 3, the signal applied to the delay 70 from the up-converter 60 through the divider 50 is amplified into a signal of a constant magnitude in the first amplifier 71. The signal amplified from the first amplifier 71 is applied to a first phase shifter 72 and the phase is converted to an analog filter 73. The analog filter 73 filters the signal applied from the first phase shifter 72 to time-delay the signal for a predetermined time and applies it to the combiner 52.

1, 2, and 4, the signal, which is a radio frequency applied to the delay 70 from the up-converter 60 through the divider 50, is applied to the intermediate frequency generating unit 74 to be an intermediate frequency. Is converted to. The signal converted into the intermediate frequency by the intermediate frequency generator 74 is applied to the first A / D converter 75, converted into a digital signal, and then applied to the first controller 76. The first controller 76 stores the digital signal applied from the first A / D converter 75 in the first memory unit 77 for a predetermined time (1/8 chip to 1/2 chip) and then outputs the digital signal. The digital signal output from the first controller 76 is applied to the first D / A converter 78, converted into an analog signal, and then applied to the radio frequency generator 79. The radio frequency generator 79 converts an intermediate frequency applied from the first D / A converter 78 into a radio frequency. The radio frequency signal converted by the radio frequency generator 79 is applied to the second phase shifter 80, and the second phase shifter 80 is applied to the combiner 52 after phase shifting the signal. do.

Referring to FIGS. 1, 2, and 5, a signal having an intermediate frequency applied from the sector interface card 40 to the delay 70 through the divider 50 is digitally output from the second A / D converter 81. Is converted into a signal. The signal converted into a digital signal by the second A / D converter 81 is applied to the second controller 82, and the second controller 82 receives the signal applied from the second A / D converter 81. The second memory unit 83 stores the output for a predetermined time (1/8 chip to 1/2 chip). The signal output from the second controller 82 is applied to the second D / A converter 84, and the second D / A converter 84 converts the digital signal from the second controller 82 into an analog signal. To. The transmission signal, which is an output analog signal applied from the second D / A converter 84, is applied to the third phase shifter 85, and the third phase shifter 85 changes the phase of the transmission signal so as to combine the combiner ( 52).

Referring to FIGS. 1 and 6, the analog synthesis card 30 synthesizes I signals applied from a plurality of channel cards 20 to make a first I signal, and the first I signal is a 3D / A. In the converter 31, it is converted into an analog signal. In addition, the analog synthesis card 30 synthesizes the Q signals applied from the plurality of channel cards 20 to produce a first Q signal, and the first Q signal is converted into an analog signal by the 5D / A converter 33. do. The first I signal applied from the 3D / A converter 31 and the first Q signal applied from the 5D D / A converter 33 are combined in the first synthesis unit 35 to output the first I + Q signal. Done.

The first I signal applied to the 3D / A converter 31 is simultaneously applied to the third control unit 38, and the third control unit 38 supplies the first I signal to the third memory unit 38a. The time is stored for 1/8 chip to 1/2 chip. The second I signal, which is stored for a predetermined time (1/8 chip to 1/2 chip) in the third memory unit 38a and is delayed, is output by the third control unit 38. The second I signal delayed for a predetermined time by the third controller 38 is converted into an analog signal by the 4D / A converter 32. The first Q signal applied to the fifth D / A converter 33 is simultaneously applied to the fourth control unit 39, and the fourth controller 39 sends the first Q signal to the fourth memory unit 39a. Temporarily save. The second Q signal, which is stored for a predetermined time in the fourth memory unit 39a and is delayed, is output by the fourth control unit 39. The second Q signal delayed for a predetermined time by the fourth controller 39 is converted into an analog signal by the sixth D / A converter 34. The second I signal converted into an analog signal in the 4D / A converter 32 and the second Q signal converted into an analog signal in the 6D / A converter 34 are synthesized as one in the second synthesizer 36. It becomes a 2nd I + Q signal.

The second I + Q signal is a signal delayed for a predetermined time from the first I + Q signal, and the first I + Q signal and the second I + Q signal are synthesized as one in the third synthesis unit 37 and then output to the sector interface card 40.

Referring to FIG. 7, the CDMA analog signal, which is a transmission signal, is divided into a first transmission signal and a second transmission signal by the divider 50 (first step S100). The first transmission signal of the two signals separated by the divider 50 is applied to the combiner 52 (second step S200). Among the two signals separated by the divider 50, the second transmission signal is applied to the delay 70, delayed for a predetermined time, and then applied to the combiner 52 (third step S300). The combiner 52 combines the first transmission signal applied from the divider 50 and the second transmission signal applied from the delay 70 (fourth step S400) and outputs the same through the base station antenna 95. (Fifth step S500). The first transmission signal and the second transmission signal output through the base station antenna 95 are applied to a terminal (not shown) through various multipaths. In the terminal, the first transmission signal and the second transmission signal among the signals applied through the multipath are continuously applied to the terminal at a predetermined time interval, thereby obtaining a time diversity effect and unnecessary handoff from the terminal. The call rate can be improved by preventing hand off.

As can be seen from the above description, the present invention separates a transmission signal into two transmission signals by connecting a divider, a delay, and a combiner to a sector interface card or an up counter constituting a signal transmission apparatus of a base station, and then to one signal. Time delays for a certain time, and combines the time-delayed transmission signal with the time-delayed transmission signal in the combiner. When the synthesized transmission signal is transmitted through the base station antenna, the non-time delayed transmission signal and the time delayed transmission signal are applied to the terminal, and thus the reception rate of the terminal is greatly improved by the improved time diversity effect.

Claims (6)

A first step of separating a CDMA analog signal, which is a transmission signal, into a first transmission signal and a second transmission signal through a divider; A second step of applying a first transmission signal of the two signals separated in the first step to a combiner for synthesizing the applied signal; A third step of applying a second transmission signal of the two signals separated in the first step to a delay unit and applying a delay to the combiner for a predetermined time; And a fourth step of synthesizing the first transmission signal and the second transmission signal applied through the second step and the third step and outputting the same through an antenna. A base station controller for controlling the operation of the base station, a plurality of channel cards for generating I and Q signals from the signal applied from the base station controller, a plurality of I signals and Q signals applied from the plurality of channel cards into one I signal And an analog synthesis card to combine with the Q signal, a sector interface card for converting the I and Q signals applied from the analog synthesis card to the antenna area of the base station, an upconverter for converting the frequency applied from the sector interface card, and the up signal. A base station transmitter comprising a linear power amplifier for amplifying a magnitude of a frequency applied from a converter and outputting a transmission signal through a base station antenna, the base station transmission apparatus being connected next to the sector interface card or upconverter and separating the transmission signal into two signals. Dividers to make; A delay for time-delaying one transmission signal applied from the divider for a predetermined time; And a combiner which combines one transmission signal applied from the divider and the other transmission signal applied from the delay. 3. The apparatus of claim 2, wherein the delay comprises: a first amplifier for amplifying a signal applied from the upconverter through a divider; A first phase shifter for changing a phase of a signal applied from the first amplifier; And an analog filter for filtering the signal applied from the first phase shifter to time-delay the signal for a predetermined set time and applying the signal to the combiner. 3. The apparatus of claim 2, wherein the delay comprises: an intermediate frequency generator for converting a signal, which is a radio frequency applied from an upconverter through a divider, into an intermediate frequency; A first A / D converter for converting an intermediate frequency applied from the intermediate frequency generator into a digital signal; A first control unit connected to the first A / D converter and configured to temporarily store and output a signal in a first memory unit; A first D / A converter converting a signal applied from the first controller into an analog signal; A radio frequency generator for converting an intermediate frequency applied from the first D / A converter into a radio frequency; And a second phase shifter for changing a phase applied from the radio frequency generator to a combiner. 3. The apparatus of claim 2, wherein the delay comprises: a second A / D converter for converting an intermediate frequency applied from a sector interface card through a divider into a digital signal; A second controller for temporarily storing and outputting a signal applied from the second A / D converter to a second memory unit; A second D / A converter converting a signal applied from the second controller into an analog signal; And a third phase shifter which phase shifts the signal applied from the second D / A converter and applies it to the combiner. The method of claim 2, wherein the analog synthesis card outputs a first I + Q signal by combining a first I signal and a first Q signal, each of which combines I and Q signals applied from a plurality of channel cards. 1 After combining the second I signal and the second Q signal, each of which is delayed for a predetermined time by the delay function by the delay function and outputs the second I + Q signal, the first I + Q signal and the second I + Q signal are combined. Signal transmission apparatus of the base station characterized in that the output to synthesize one.