KR960014674B1 - Fader for mobile telecommunication - Google Patents

Abstract

The forward link RF channel simulator apparatus comprises: a first and second fading means 202, 205 for outputting and fading the high output signal sent from a first and second base station 201, 204 to make an input level to be possible; a first and second fading means 203, 206 for inputting a fading control variable, and outputting and fading the signal inputted from the first and second fading means 202, 205; a routing means 207 for outputting to a plurality of mobile station by inputting the output signals from the first and second fading means 203, 206, and outputting the sending signals from each mobile station into a first and second base station 203, 204; and a control means 208 for outputting a fading control variable into the first and second fading means 203, 206.

Description

Wireless channel simulator device with fader for mobile communication

1 is a block diagram of a conventional radio channel simulator.

2 is a block diagram of a wireless channel simulator apparatus of a forward link according to the present invention.

3 is a block diagram of a reverse channel radio channel simulator apparatus according to the present invention;

4 is a detailed block diagram of a route according to the present invention.

* Explanation of symbols for main parts of the drawings

201, 204, 301, 105: base station 209 to 212, 311 to 314: mobile station

202, 205, 302, 306: Attenuator

203, 206, 303, 304, 307, 308: FADER

207, 309: root 208, 310: computer

The present invention relates to a fader embedded wireless channel simulator apparatus for mobile communication.

The call quality of the base station and the mobile station link in the mobile communication system depends on the propagation environment due to various factors. That is, the radio waves reaching each antenna change not only by basic attenuation with distance, but also by multipath fading caused by buildings and other reflectors, and slow fading that changes with time in the same area. Therefore, there is a need for a wireless channel simulator apparatus capable of artificially creating and testing such a natural propagation environment for testing the call quality of a base station and a mobile station link in a mobile communication system.

However, reproducing the above situation in order to analyze an actual mobile communication system has a problem requiring a considerable field test.

Therefore, there is a need for an RF channel simulator device that can artificially create a natural propagation environment.

In manufacturing the above-described radio channel simulator, the apparatus shown in FIG. 1 is conventionally used.

1 is a configuration diagram of a conventional radio channel simulator, in which a transmitted radio frequency (RF) signal is input to mixer # 1 102 through a signal line 101 and a local oscillation signal input from an external signal generator. Is input to mixer # 1 102 and an interediate frequency (IF) signal that is frequency down at mixer # 1 (102) passes through fader (104), followed by mixer # 2 (106). It is mixed with the same signal as the local oscillation signal of # 1 (102) and outputs an RF input frequency originally input as an output signal.

In FIG. 1, 101, 103, 105, 107, 108, and 109 are signal lines connecting the input / output and each block, of which 108 is the signal line connected to the external signal generator and mixer # 1 (102) and mixer # 2 (106). ) Are commonly connected. In addition, 109 is a signal line for controlling the fader and the computer 110.

The fader 104 receives and performs a fading control variable from the computer 110 to process the frequency-down signal in the intermediate frequency (IF) band.

Conventional radio channel simulators are simple faders for the function of multipath fading and rayleigh fading and function on each of the forward link or reverse link that the mobile station receives via the fader when the base station transmits. Exerted. In addition, in the case of actually emitting radio waves, the transmission power is very large, and since the separation distance of the transmitting and receiving antenna is several meters, the base station receiver is affected by the transmitter. That is, the situation in which part of the transmission signal is input to the reception signal has not been considered, and there is a problem that simulation cannot be performed in a full duplex state in which the base station and the mobile station communicate with each other simultaneously.

Accordingly, the present invention has been made in order to solve the above problems of the prior art, a mobile communication fader-embedded wireless channel simulator device capable of simulating a radio channel in a two-way communication state between the base station and the mobile station without actually emitting radio waves into the air. The purpose is to provide.

In order to achieve the above object, the present invention provides a wireless channel simulator apparatus for a forward link, comprising: first and second attenuation means for attenuating and outputting a high output signal transmitted from a first base station and a second base station to an input level; First and second fading means for receiving a fading control variable and fading and outputting a signal input from the first and second attenuating means; Routing means for receiving the output signals of the first and second fading means and outputting them to a plurality of mobile stations, and outputting signals transmitted from each mobile station to the first and second base stations; And control means for outputting a fading control variable to the first and second fading means, wherein the reverse link radio channel simulator apparatus receives signals transmitted from a plurality of mobile stations, and receives the first and second base stations. Routing means for receiving a signal attenuated by the output signal and outputting the signal to a plurality of mobile stations; A plurality of fading means for receiving a fading control variable and fading the mobile station signal input from the routing means to the first and second base stations; First and second attenuating means for attenuating the high output signal transmitted from the first and second base stations to a level capable of being input to the routing means; And control means for outputting fading control variables to the plurality of fading means.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 2 to 4.

2 is a block diagram of a forward link radio channel simulator from a base station to a mobile station according to the present invention.

The present invention is connected to the output of the base station via a cable, and also connected to the mobile station via a cable to test the operating state of the base station and the mobile station without emitting a radio frequency.

As shown in the figure, the present invention is connected to two base stations 201 and 202 and a plurality of mobile stations 209 to 212, for simulation of inter-sector or inter-cell handoff.

First, since the signal transmitted from the base station # 1 201 is a signal passed through the high power amplifier, the attenuator 202 attenuates and inputs the input level to the fader 203. The output of the fader 203 is input to Tx1, which is the first terminal of the route 207, and its output is input to each of the mobile stations 209 to 212 through the 7 to 10 terminals of the route 207.

Since the base station and the mobile station are bidirectionally communicating, the signals transmitted from each mobile station are input again through the 7 through 10 terminals of the route 207, and the 2, 3, 5, 6 terminals of the base station # 1 201 through the receiving terminals 2, 3, 5, 6, respectively. 3 terminals and 2 and 3 terminals of base station # 2 204 are input.

Similarly, since the signal transmitted from the base station # 2 204 passes through the high power amplifier, the signal is attenuated to a level that can be input from the fader 206 through the attenuator 205 and then input to the fader 206.

The output of the fader 206 is input to Tx2, which is the fourth terminal of the route 207, and its output is input to each of the mobile stations 209 to 212 through the route 207, 7 to 10 terminals.

Since the base station and the mobile station are in bidirectional communication, signals transmitted from each mobile station are input again through the terminals 7 to 10 of the route 207, and 2 and 3 of the base station # 1 201 through terminals 2, 3, 5, and 6, which are receiving terminals. Inputs are made at terminals 2 and 3 of the base station # 2 204. Here, the faders 203 and 206 receive a fading control variable from the computer 208 for processing a signal down-frequency in the intermediate frequency band through the attenuators 202 and 205 through the control signal lines which are terminals 2, respectively. Perform.

3 is a block diagram of a reverse link radio channel simulator from a base station to a mobile station according to the present invention.

Similarly to FIG. 2, the signals transmitted from the mobile stations 311 to 314 are input through the 7 to 10 terminals of the route 309, and the signals of the faders (303, 304, 307, 308) are received through the 2, 3, 5, and 6 terminals. It is input to each 1 terminal.

Each of the faders 303, 304, 307, and 308 outputs a signal input from the route 309 to the receiving end of the base stations # 1, # 2 (301, 305). Here, each of the faders 303, 304, 307, and 308 receives a fading control variable from the computer 310 through a control signal line, which is a second terminal, to perform a fading function.

Since the mobile station and the base station communicate in both directions, the signal transmitted from each base station attenuates the transmission power level again in the attenuators 302 and 306, and then enters the mobile stations 311 to 314 through the first terminal 4 of the route 309. do.

4 is a detailed block diagram of a route (207 in FIG. 2, 309 in FIG. 3) according to the present invention, wherein the distributors 401 to 408 are two way splitters, and the distributors 409 and 410 are 4-way splitter.

Terminals 1, 2, 3 and 4, 5, 6 are connected to the base station, where terminals 1 and 4 are connected to the base station transmitting side, and terminals 2, 3, 5, 6 are connected to the base station receiving side. Terminals 7 to 10 are each connected to a mobile station.

The signal transmitted from the base station through the terminal 1 is sent to the distributor 409 through the distributor 405, and another path passes through the distributor 406 to terminals 2 and 3 to the receiving side of the base station. Is entered. The signal passing through the distributor 409 is sent to each mobile station through the distributors 401-404.

Similarly, the signal transmitted from the base station through the terminal 4 is sent to the distributor 410 through the distributor 408, and another route is output through the distributor 407 to terminals 5 and 6 and input to the receiving side of the base station. do.

The signal passing through the distributor 410 is sent to each mobile station through the distributors 401-404.

Therefore, the present invention configured and operated as described above can substantially reduce the field test time for mobile communication system analysis by realizing the radio wave environment in mobile communication without actually generating radio waves, and by constructing simple components. There is an economic advantage.

Claims (2)

First and second attenuating means (202, 205) for attenuating and outputting a high output signal transmitted from the first and second base stations (201, 204) to an inputable level; First and second fading means (203, 206) for receiving a fading control variable and fading and outputting a signal input from the first and second attenuating means (202, 205); Routing means (207) for receiving the output signals of the first and second fading means (203, 206) and outputting them to a plurality of mobile stations, and outputting signals transmitted from each mobile station to the first and second base stations (203, 204); And control means (208) for outputting fading control variables to said first and second fading means (203, 206). Routing means 309 for receiving signals transmitted from a plurality of mobile stations, for receiving signals attenuated by the output signals of the first and second base stations 301 and 305 and outputting the signals to the plurality of mobile stations; A plurality of fading means (303, 304, 307, 308) for receiving a fading control variable and fading the mobile station signal input from the routing means (309) to the first and second base stations (301, 305); First and second attenuating means (302, 306) for attenuating the high output signals transmitted from the first and second base stations (301, 305) to a level capable of being input to the routing means (309); And control means (310) for outputting fading control variables to the plurality of fading means (303, 304, 307, 308).