KR100345027B1 - Method and apparatus for measuring radio-wave - Google Patents

Abstract

According to the present invention, it is possible to accurately locate a location where a base station is to be installed by using CDMA (Code Division Multiple Access) propagation, thereby enabling the construction of an efficient CDMA network.

The base station candidate site is provided with a transmission device capable of inserting a pilot signal, a synchronization or paging signal, and the like into the CDMA signal, and a reception device (e.g., a normal terminal) capable of receiving the CDMA signal is installed in the vehicle, and the Ec / Measure Io and RSSI. In this way, each Ec / Io and RSSI are measured for neighboring preliminary candidate base stations, the amount of interference between the base stations is calculated by a PC, and the Ec / Io values are obtained considering the interference of other base stations. After that, the virtual traffic is set to simulate the interference amount of the own cell, and once again, the Ec / Io value is calculated and displayed on a map on the PC, so that the cell area when actually building a commercial network can be reflected. By knowing the shadow area in this way, it is possible to reduce the trial and error of selecting the optimal base station location, antenna direction and gain, and thus to achieve rapid network construction and economical network construction.

Description

Radio wave measuring method and apparatus therefor {METHOD AND APPARATUS FOR MEASURING RADIO-WAVE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio wave measuring method and apparatus thereof, and more particularly, to a radio wave measuring method and apparatus capable of economically and effectively performing radio wave measurement and coverage prediction required for a network cell system of a mobile communication system.

In general, radio measuring equipment systems are used to measure the distance of radio waves in advance before establishing a radio station or base station when constructing a wireless network. In this way, by measuring the distance of the radio wave in advance, it is possible to reduce the trial and error at the time of network construction, it is possible to build an economical and quality network.

At present, there are two types of CDMA coverage measuring devices in Korea. First, there is a radio wave measuring device (see FIG. 1) that performs radio wave measurement using CW signal, and second, a radio wave measuring device (see FIG. 2) that makes a measurement by compensating the gain spread to 1.23Mhz using this CW signal. have.

In addition, a foreign apparatus includes a radio wave measuring apparatus (see FIG. 3) that directly transmits a CDMA signal, receives the signal to a CDMA receiving apparatus, and directly measures Ec / Io.

EMBODIMENT OF THE INVENTION Hereinafter, the radio wave measuring apparatus which concerns on these conventional examples is demonstrated with reference to FIGS.

First, a radio wave measuring apparatus according to a conventional example will be described with reference to FIG. 1 is a block diagram of a radio wave measuring apparatus according to a conventional example in which radio wave measurement is performed using a CW (Continuous Wave) signal.

The radio wave measuring device includes a CW signal generator 10 for generating a CW signal, a CW signal amplifier 11 for amplifying a CW signal, a spectrum analyzer 12 for receiving a CW signal, and a CW signal. PC (RSSI measurement; 13) for measuring the received intensity of the display on the map and a GPS receiver 14 for indicating the current position. The radio wave measuring device according to the conventional example configured as described above is configured to send a received strength (RSSI) value of the received radio wave to the analysis device and display it together with the GPS data.

This radio wave measuring apparatus is mainly used for wireless data communication, coverage measurement of CT-2, TRS, etc., and uses only radio wave reception intensity (RSSI). However, since the CDMA system has a system characteristic in which the coverage changes due to the interference of radio waves other than the user, the coverage is determined by the Ec / Io value. Where Ec is carrier energy and Io is defined as follows.

Io = Nt + Isc + Ioc... … … (One)

Where Nt is the thermal noise spectral density,

Isc is the in-cell interference spectral den

sity),

Ioc is the outer-cells interference spectral

density).

Therefore, when Nt is constant, the value of Ec / Io decreases as Io increases, thereby narrowing cell coverage. Therefore, when Ec is constant, the values of the received RSSI and the Ec / Io may be inversely related, and therefore, the radio measuring device using only the RSSI is not actually a suitable measuring device for measuring the expected coverage in the CDMA system.

Next, a radio wave measuring apparatus according to another conventional example will be described with reference to FIG. 2. 2 is a block diagram of a radio wave measuring apparatus according to another conventional example in which a CW signal is simulated by a CDMA signal to perform radio wave measurement.

The radio wave measuring apparatus includes a frequency generator 20 for generating a CW signal (PCS frequency) in the 1.8 Ghz band, which is a PCS dedicated frequency band, a CW signal amplifier 21 for amplifying the signal, and a strength of the CW signal. Power meter 22, a PC (for RSSI measurement and CDMA simulation; 23) for simulating Ec / Io using the RSSI measured by the power meter 22 and displaying the GPS data on a map and receiving GPS data It consists of a GPS receiver 24.

The radio measuring apparatus first measures RSSI with a 30Khz resolution bandwidth, and then compensates 16dB for each band at 1.23Mhz. Here, 16 dB is a value calculated from 10log (1.23Mhz / 30Khz). Then, the interference of its own cell is calculated in consideration of the digital gain set in the overhead channel system. However, this radiometer does not consider interference of other cells at all, and also interference effects caused by the effects of path loss differ ence and phase distortion between frequencies, and CDMA in a magnetic cell. This device does not consider any interference between channels.

Next, a radio wave measuring apparatus according to another conventional example will be described with reference to FIG. 3. 3 is a block diagram of a radio wave measuring apparatus according to another conventional example in which radio wave measurement is performed using only a pilot signal in a CDMA signal.

The radio wave measuring apparatus includes a CDMA signal (PN) generator 30 for generating a CDMA pilot signal, a CDMA signal amplifier 31 for amplifying a 1.23 MHz band, a CDMA pilot signal receiver 32 for receiving a CDMA pilot signal, This receiver collects Ec / Io data and displays it on the screen, and is equipped with a PC equipped with S / W with a pilot signal scanning function (for Ec / Io display; 33), and a GPS receiver for synchronizing transmitters and receivers ( 34).

However, this radiometer does not consider the overhead channel and does not reflect the Isc at all and does not consider the interference of another cell, so the Ec / Io value does not reflect the Ec / Io value of the actual commercial system. There are many differences with, and thus the coverage also shows a lot of differences. In addition, there is a problem that H / W becomes expensive because GPS is attached to the transmission / reception equipment in order to transmit and receive the CDMA signal and synchronize the transmitter and the receiver.

As a result, in order to solve the problem of the radio wave measuring apparatus according to the conventional example described above, there is no other good method other than the method of actually making and testing a base station and a mobile station. However, when this method is used, there is a problem that the mobility is low, and the equipment itself becomes too expensive, and in particular, it is expensive to make a receiver.

As described above, the radio wave measuring apparatus according to the conventional example does not adopt a method of calculating Ec / Io by simultaneously reflecting Isc and Ioc. Therefore, the interference limit characteristic, which is one of the CDMA characteristics, is not sufficiently reflected, and in order to solve this problem, it is necessary to create a propagation environment almost identical to the actual system. However, in order to create a radio wave environment almost identical to the actual system, there are many problems such as heavy transmission equipment and all protocols for communicating with the terminal to be matched almost identical to the actual system.

In order to solve this problem, the present inventors have found a minimum packet necessary to perform only a function of measuring the Ec / Io and RSSI of a receiver (terminal) in a CDMA transmitting / receiving device, that is, among pilot, synchronization and paging messages. We found that it was essential to deliver only the necessary messages to the receiver. In addition, it was found that after the preliminary base station was measured sequentially, the Isc value of each other was calculated, and the Ioc value could be calculated through traffic simulation.

The present invention has been made in consideration of the above-described points, and after sequentially measuring base stations, calculating Isc values of each other, and calculating Ioc values through traffic simulation, radio wave measurement and the radio wave measurement required for the network system of the mobile communication system and An object of the present invention is to provide a radio wave measuring method and apparatus capable of economically and effectively performing coverage prediction.

1 is a block diagram of a radio wave measuring apparatus according to a conventional example of performing radio wave measurement using a CW (Continuous Wave) signal;

2 is a block diagram of a radio wave measuring apparatus according to another conventional example in which a CW signal is simulated with a CDMA signal to perform radio wave measurement;

3 is a block diagram of a radio wave measuring apparatus according to another conventional example in which radio wave measurement is performed using only a pilot signal in a CDMA signal;

4 is a block diagram of a radio wave measuring apparatus according to the present invention for performing radio wave measurement using a pilot signal / synchronous signal to a CDMA signal;

5 is a view for explaining the operation of optimizing the network using the radio wave measuring apparatus according to the present invention.

<Description of the symbols for the main parts of the drawings>

10 --- CW signal generator, 11 --- CW signal amplifier,

12 --- Spectrum Analyzer, 13 --- PC (for RSSI measurement),

14 --- Global Positioning System (GPS) receiver,

20 --- CW signal (PCS frequency) generator, 21 --- CW signal (PCS frequency) amplifier,

22 --- power meter,

23 --- PC (for RSSI measurement and CDMA simulation),

24 --- GPS receiver, 30 --- CDMA signal (PN) generator,

31 --- CDMA signal (1.23Mhz) amplifier,

32 --- CDMA signal (pilot signal) receiver, 33 --- PC (for Ec / Io display),

34 --- GPS receiver,

40 --- CDMA signal (pilot signal / synchronous signal) generator,

41 --- CDMA signal amplifier, 42 --- mobile phone (mobile station),

43 --- PC (for RSSI, Ec / Io measurement and simulation),

44 --- GPS receiver,

100-1, 100-2, 100-3,... , 100-n --- spare base station,

200 --- Test vehicle.

In order to achieve the above object, the radio wave measuring method according to the present invention, before installing a base station for establishing a communication network, radio waves for measuring the radio wave by selecting a predetermined location of the equipment station to be installed in order to measure the distance that the radio wave in advance In the measuring method, Ec (carrier energy) / Io and RSSI (receiving strength of received radio wave) are sequentially measured using signals received at respective positions of the preliminary base station installation, and these values are mutually measured. Isc (interference spectral density in one cell) value is calculated and Ioc (interference spectral density in another cell) value is calculated using traffic simulation.

In addition, the radio wave measuring apparatus according to the present invention is a radio wave measuring apparatus for measuring radio waves by selecting a predetermined position for installing an equipment station in order to measure the distance of radio waves in advance before installing a base station for establishing a communication network. A transmitting device 41 which transmits only the minimum message necessary to perform a function of measuring Ec (carrier energy) / Io and RSSI (receiving strength of received radio waves), and an Ec / Receivers 42 and 44 for measuring Io and RSSI, and outputting these measured values, and using the measured values, calculates Isc (interference spectral density in own cell) values between preliminary base stations, and simulates traffic. And processor means 43 for calculating Ioc (interference spectral density) values of other cells and displaying them on a map together with the values measured by the receiver. It is characterized by.

The receiving device is characterized in that the mobile terminal used in a commercial network.

(Example)

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

FIG. 4 is a block diagram of a radio wave measuring apparatus according to the present invention for performing radio wave measurement using a pilot signal / synchronous signal to a CDMA signal, and FIG. 5 is an operation of optimizing a network using a radio wave measuring apparatus according to the present invention. It is a figure for demonstrating.

The radio wave measuring apparatus of the present invention includes a signal generator 40 for generating a signal capable of measuring only Ec / Io and RSSI, that is, a CDMA signal (pilot signal / synchronization signal), as shown in FIG. A CDMA signal amplifier 41 for amplifying the CDMA signal (pilot signal / synchronization signal) generated at 40, and a mobile telephone for measuring Ec / Io and RSSI using the signal received from the CDMA signal amplifier 41 ( 42), a GPS receiver 44 for displaying the received data on the map, and calculating the Isc values between the preliminary base stations and calculating the Ioc values using the traffic simulation, and calculating these values along with the GPS data on the map. PC (RSSI, Ec / Io measurement and simulation) 43 for display.

The radio wave measuring apparatus according to the present invention generates a pilot channel using the CDMA signal generator 43 as shown in Fig. 4, and then, unlike the actual system, does not use GPS time (the existing CDMA system is synchronous. GPS time is used during handoff) Create a synchronization channel using its own system clock, insert the current system time into the synchronization channel, amplify it using the CDMA signal amplifier 41, and then antenna (Ant). Send using. In this way, the mobile telephone 42 actually considers that the CDMA signal has been received from the base station (BTS), measures the Ec / Io and RSSI, and extracts the PN information by inserting the current PN number information into the paging channel. can do.

The mobile phone 42 measures the Ec / Io and RSSI, and then outputs the information on the DM port when a request for these two values is received from the PC. Therefore, the desired Ec / Io and RSSI can be easily obtained by sending a command requesting a measurement command from the PC to the serial port at regular intervals.

At this time, there are two methods of measuring Ec / Io by the terminal. That is, the transmitter generates a CDMA signal as shown in FIG. 3, but divides into two methods, a method of sending only a pilot signal and a synchronization signal to a terminal as shown in FIG. 4, and a method of sending three signals such as a pilot signal, a synchronization signal, and a paging signal. Can be. If the paging signal is not sent, the terminal returns to the pilot search state for the first time after 3 seconds. Therefore, the terminal has no choice but to calculate the Ec / Io value every 3 seconds, but there is no problem in radio wave measurement even if the measurement is performed at 3 second intervals. Therefore, in measuring radio waves, a paging signal is sent when radio measurement requires accuracy for use, and a paging signal is not sent when measurement is performed at intervals of 3 seconds, thereby significantly reducing manufacturing costs. Can be.

The method for calculating Ec / Io and RSSI by paying attention to the interference of other base stations is performed when there are n (n ≧ 2) spare base stations as shown in FIG. 5 [BTS1 (100-1) and BTS2 (100-2). , BTS3 (100-3),... . BTSn (100-n)], Ec / Io of the terminal measured by the mobile telephone installed in the measurement test vehicle 200 at the first base station is referred to as (Ec1 / Io1), and Ec / Io of the terminal measured by the nth base station is When (Ecn / Ion), Ioc of the first base station can be expressed as the following equation.

Ioc1 = Ioc2 + Iocn... … … (2)

Meanwhile, the total base station ERP is

Total base station ERP = call + pilot + paging + sync… … … (3)

Therefore, when the value of Ec1 / Io1 received by the first base station is A and the reception power of the terminal is RSSI1, Isc1 is expressed as follows.

Isc1 = A x Ec1... … … (4)

Isc = Call + Paging + Sync

If you do not send a paging channel, calculate the paging power by using the percentage of power allocated to the paging channel in the total base station ERP normally set by the system, add it to Isc, and calculate the call channel in the same way. Multiply the number of calls set by S / W operator and add it to Isc. In this way, if Isc and Ioc are obtained and then Ec / Io value is recalculated, Ec / Io considering the call channel can be obtained.

As mentioned above, although this invention demonstrated the case where CDMA radio wave is measured as an example, it can be variously modified and implemented in the range which does not deviate from the summary of this invention, without being limited to this. For example, the present invention can be applied to a radio wave measurement system using CDMA signals such as IMT2000 and WLL other than CDMA radio waves.

According to the present invention, a radio wave measuring method and apparatus capable of constructing an optimal CDMA network through accurate CDMA radio wave measurement and simulation can be provided.

Claims (5)

In the radio wave measuring method of measuring the radio wave by selecting the predetermined position of equipment station installation in order to measure the distance which radio wave advances before installing a base station for establishing a communication network, Ec (carrier energy) / Io and RSSI (receive strength of received radio waves) are sequentially measured using the signals received at each of the scheduled locations of the spare base station, and these values are used to determine A radio wave measuring method comprising calculating an interference spectral density value and calculating an Ioc (interference spectral density of another cell) value using a traffic simulation. In the radio wave measuring apparatus which measures the radio wave by selecting the predetermined position of equipment station installation in order to measure the distance which radio wave advances before installing the base station for establishing a communication network, A transmitter 41 for transmitting only the minimum messages necessary to perform the functions of measuring Ec (carrier energy) / Io and RSSI (receive strength of received radio waves), Receivers 42 and 44 for measuring Ec / Io and RSSI using the signals received from the transmitter and outputting these measured values; The measured values are used to calculate Isc (interference spectral density) values between the preliminary base stations, and to calculate Ioc (interference spectral density of other cells) using traffic simulation, and these values are calculated by the receiver. Radio measuring apparatus characterized in that it comprises a processor means for displaying on the map with the value measured in (43). The radio wave measuring apparatus according to claim 2, wherein the receiver includes a mobile terminal used in a commercial network. The method of claim 1, wherein the measurement of the Ec / Io and RSSI takes about 3 seconds to wait for a paging signal after acquiring a pilot and a synchronization channel included in the received signal, and Ec (carrier without a paging signal). And measuring Ec / Io and RSSI at intervals of three seconds using characteristics capable of measuring energy) / Io and RSSI (receive intensity of received radio waves). The Ec / Io and RSSI of claim 1, wherein the Ec / Io and RSSI are measured by using three overhead channels, such as a pilot, a synchronization channel, and a paging channel, included in the received signal. Radio wave measuring method, characterized in that.