KR20030091376A - Bit error rate tester in Spread Spectrum telecommunication system and method thereof - Google Patents

Abstract

PURPOSE: An apparatus for measuring a bit error rate in a spread spectrum communication system and a method therefor are provided to grasp the state of a wireless interval of the spread spectrum communication system by checking the bit error rate. CONSTITUTION: A transmission unit(310) has a bit error rate test pattern generating unit(311) and a Tx modem(315). The bit error rate test pattern generating unit(311) receives a transmission traffic clock signal and a transmission PN(Pseudo random Noise) period start signal, and generates a period bit error rate test pattern. The Tx modem(315) transmits the bit error rate test pattern. A reception unit(320) has a demodulating unit(325), a bit error rate test pattern generating unit(323), a comparing unit(327), and a bit error calculating unit(329). The demodulating unit(325) demodulates the received bit error rate test pattern. The bit error rate test pattern generating unit(323) receives a reception PN period start signal, and generates an Rx bit error rate test pattern. The comparing unit(327) receives the signals outputted from the demodulating unit(325) and the bit error rate test pattern generating unit(323), and compares the received signals. The bit error calculating unit(329) calculates a bit error by a signal received from the comparing unit(327).

Description

Bit error rate tester in Spread Spectrum telecommunication system and method

The present invention relates to a field for checking the quality of a communication path in a direct spread spectrum communication system, and more particularly, a bit error rate measuring apparatus in a direct spread spectrum communication system for calculating a bit error rate by generating a pattern for testing the bit error rate between the transmission and reception unit; It is about how.

1 is a block diagram of a transmitter 110 and a receiver 120 of a conventional spread spectrum communication system. When the traffic data is transmitted through the Tx modem 111, the Rx modem 121 receives and demodulates the traffic data. At 123, the signal is demodulated.

Direct Sequence Spread Spectrum (DSSS) communication system is a survivability that provides multiple transmission technology over wireless to wired network to provide advantages of short-range operation over wireless in network. A small-area short-range carrier communication equipment having a, comprising: a wireless unit for wirelessly transmitting data processed in the baseband, a logic unit for processing the data processed in the baseband and controlling the system and a power supply unit for supplying power to the whole system It is composed. The main specifications are in the frequency range of 1.71 to 1.84 [GHz] and transmission rates of 256, 512 or 1024 [kbps]. The mastery ranges 12 km from the line of sight. It can be used as a relay function to extend communication distance. In addition, the conventional system can only grasp the strength of the received signal, it was not able to accurately know the state of the wireless section communication path.

An object of the present invention is to provide an apparatus and method for measuring a bit error rate in a spread spectrum communication system using a bit error rate test pattern to solve the above problems.

Another object of the present invention is to provide a computer-readable recording medium having recorded thereon a program for executing the method on a computer.

1 is a block diagram of a transmitter and a receiver of a conventional spread spectrum communication system.

2 shows a block diagram of a spread spectrum communication system.

3 is a diagram illustrating a bit error rate measuring apparatus in a spread spectrum communication system according to the present invention.

4 is a flowchart illustrating a method for measuring bit error rate in a spread spectrum communication system according to the present invention.

In the spread spectrum communication system according to the present invention for achieving the above object, the bit error rate measuring apparatus is a transmission bit error test pattern generation unit for generating a periodic bit error rate test pattern by receiving a transmission traffic clock signal and a start signal of a transmission period. And a Tx modem for transmitting the bit error rate test pattern; a demodulator for demodulating the received bit error rate test pattern, receiving an Rx traffic clock and a PN period start signal to generate an Rx bit rate test pattern. Bits for calculating bit errors based on the signal received from the comparator and the comparator for receiving and comparing the signals output from the RX bit error test pattern generator and the demodulator and the RX received bit error test pattern generator, respectively It includes a receiver including an error calculator.

Bit error rate measuring method in a spread spectrum communication system according to the present invention for achieving the above object, (a) generating and transmitting a bit error rate test pattern; (b) receiving the bit error rate test pattern received bit error rate test Comparing the pattern; (c) calculating the bit error rate by counting the number of bit errors output in the step (b).

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

2 is a block diagram of a spread spectrum communication system to which the present invention is applied.

The transmission panel 220 receives the signal from the base station 210, generates a frame signal according to the control signal of the main controller 260, and detects the frame synchronization signal. The transmitter 231 outputs the generated frame signal (Tx traffic data) by performing baseband modulation, spread spectrum function, and D / A conversion. The modulator 233 amplifies a signal output from the transmitter 231 and suppresses generation of an unwanted signal with respect to the signal. The power amplifier 235 controls the forward output of the signal output from the modulator 233 and cuts off the transmission power when an error occurs. The signal output from the power amplifier 235 is transmitted to another spread spectrum communication system through the antenna 240. The signal received from another spread spectrum communication system is detected by the tuning unit 251, amplified, and processed into a first intermediate frequency. The demodulator 253 receives the first incremental frequency, removes the unwanted wave by the band filtration function, and performs automatic gain control on the intermediate frequency signal to output it. The receiver 255 performs A / D conversion and despreads the signal output from the demodulator 253 to demodulate. The transmission panel 220 transmits a signal output from the receiver 255 to the base station 210.

3 is a diagram illustrating a bit error rate measuring apparatus in a spread spectrum communication system according to the present invention.

4 is a flowchart illustrating a method for measuring bit error rate in a spread spectrum communication system according to the present invention.

3 and 4 will be described together.

The bit error rate check point (bit error rate test session) between the spread spectrum communication systems is an appointment between the operators of the redundancy spread communication system through the call channel, and inputs to the system using the keypad (step 410). .

The bit error rate test pattern generator 311 of the transmitter 310 generates a bit error rate test pattern of '110011001100 ....' and the start point of the bit error rate test pattern is denoted by pseudo random noise (PN). Set to coincide with the starting point of the cycle of step (step 420). That is, the transmission start point of the bit error rate test pattern is the start point of an arbitrary PN period. The rate of occurrence of the bit error rate test pattern (rate of transmission data during the bit error rate test period) is one of 256, 512 or 1024 [kbps] as programmed in advance. When the generated bit error test pattern is transmitted in 8 seconds through the Tx modem 315 through the Mux 313 (step 430), the receiver of the other system receives the signal through the Rx modem 321 and demodulates the unit 325. In operation 440, the comparison unit 327 detects an error bit by comparing the signal generated by the reception bit error test pattern generation unit 323.

The bit error calculator 329, which counts errors in 1000 reception PN period units, accumulates and stores the number of bit errors output from the comparator and reads out the error bits stored in 8 second units. The bit error rate is calculated and displayed by dividing by the number of data bits (step 450). The maximum number of bits transmitted for 8 seconds is 8192000 [bits] when 1024 [kbps], and the maximum value of the bit error calculator 329 is 8,192,000 (23 bits).

Specifies the bit error rate checking point (bit error rate test session) between two spread spectrum communication systems through the call channel. The bit error rate test session proceeds as follows. All test environments are set up previously. The baud rate test is performed only on the programmed (or setup) baud rate. The basic structure of the bit error test is repeated every 8 seconds regardless of the transmission speed. Bit error rate is calculated by counting errors based on the number of bits transmitted and received during 8 seconds.

8 seconds corresponds to 1000 PN cycles. Therefore, the number of bits transmitted for 8 seconds is shown in Table 1 below.

Baud rate, [kbps] bits duration, [㎲] Transmission bits / PN period, [bits] Transmission bit / 1000 PN cycle, [bits] Number of beat errors Observed bit error rate 256 3.90625 2048 2048000 X1 X1 / 2048000 512 1.953125 4096 4096000 X2 X2 / 4096000 1024 0.976563 8192 8192000 X3 X3 / 8192000

The units shown in Table 1 are shown in Equation 1.

[Equation 1]

Chip rate = 4.096 [Mcps] = 244.140625 [ns]

1PN period = 32768 [chips] = 125 [periods / sec] = 8 [ms]

256 [kbps] = 16 [chips / bit]

512 [kbps] = 8 [chips / bit]

1024 [kbps] = 4 [chips / bit]

The bit error rate test pattern is transmitted from the transmitter 310 at an 8 second period, and the bit error calculation is performed by accumulating counting at the receiver 320 at an 8 second period, and the receiver 320 counts a result of counting a bit error for 8 seconds. To record. The recorded result is read out and divided by the total number of transmitted data bits and displayed in terms of bit error rate.

The bit error rate test session as described above is repeatedly performed until the bit error rate test session is released from the keypad.

Bit-error rate test sessions should be at least 24 seconds long and ignore the first and last 8 seconds of results.

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, hard disk, floppy disk, flash memory, optical data storage device, and also carrier waves (for example, transmission over the Internet). It also includes the implementation in the form of. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

As described above, according to the present invention, by checking the bit error rate of the spread spectrum communication system, it is possible to grasp the state of the radio section of the communication system, and check whether the bit error of the transmission / reception data between the systems is generated by the bit error rate test pattern. It is possible to check the condition of the communication line in the wireless section such as moving or mountain.

Claims (11)

A transmission unit including a transmission bit error test pattern generation unit receiving a transmission traffic clock signal and a start signal of a transmission < RTI ID = 0.0 > P & N < / RTI > period and generating a periodic bit error rate test pattern and a TX modem for transmitting the bit error rate test pattern; And An demodulation unit for demodulating the received bit error test pattern, an Rx bit error test pattern generator for generating an Rx bit error test pattern by receiving a received traffic clock and a receiving P & C start signal, and the demodulation part and an Rx receiving bit And a receiver including a comparator for receiving and comparing the signals output from the error rate test pattern generator, and a bit error calculator for calculating a bit error based on the signal received from the comparator. Bit error measurement device. The method of claim 1, wherein the transmission bit error test pattern generation unit And a bit error rate test signal is generated by receiving a period start signal of a T-X traffic clock signal and a T-X pseudo random noise signal. The method of claim 1, wherein the reception bit error test pattern generation unit A bit error rate measurement apparatus in a spread spectrum communication system comprising receiving a cycle start signal of a received traffic clock signal and a received pseudorandom noise signal and generating a received bit error test signal. The method of claim 1, wherein the comparison unit Bit error rate measuring apparatus in a spread spectrum communication system characterized in that the output from the signal received from the transmission unit and the received bit error test pattern generated by the received bit error test pattern generation unit when a difference occurs. The bit error rate calculator of claim 1, wherein the bit error rate calculator A bit error rate measuring apparatus in a spread spectrum communication system, characterized in that the bit error rate is calculated by calculating the number of bit errors and dividing by the number of bits of the received data. (a) generating and transmitting a bit error rate test pattern; (b) receiving the bit error rate test pattern and comparing the bit error rate test pattern with a receiving bit error rate test pattern; And and (c) calculating a bit error rate by counting the number of bit errors output in step (b). The method of claim 6, And setting a transmission rate and a bit error test period and starting a bit error test session. The method of claim 6, wherein step (b) And a bit error rate test pattern for receiving the same bit error rate test pattern generated in step (a) and comparing the received bit error rate test pattern with the received bit error rate test pattern. The method of claim 6, wherein step (b) And comparing the bit values of the received bit error test pattern and the received bit error test pattern sequentially and outputting the bit values if the bit values have different bit values. The method of claim 6, wherein step (c) (c1) accumulating the number of bit errors output in step (b); And and (c2) calculating the bit error rate by dividing the number of bit errors accumulated in step (c1) by the number of transmission bits according to the transmission rate. A computer-readable recording medium having recorded thereon a program for executing the method of claim 6 on a computer.