JP2003273786A - Method and instrument for measuring delay profile, and program for measuring delay profile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately measure a delay profile in radio propagation through the use of the autocorrelation characteristic of a pseudo-random (PN) code. <P>SOLUTION: A method for measuring a delay profile uses the autocorrelation characteristic of the PN code to measure the delay profile in radio propagation. The delay profile is measured by waveform equalization concerning each of the I and Q-axies of a reception signal based on the ideal PN code, and the PN code which is received in a state where a transmitter is directly connected to a receiver or a state where transmission/reception is performed only by a single propagation route. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a delay profile measuring method, a measuring device, and a delay profile measuring program, and more particularly, to a delay profile of radio wave propagation using the autocorrelation characteristic of a pseudo random (PN) code. The present invention relates to a delay profile measuring method for measuring, a measuring device, and a delay profile measuring program.

[0002]

2. Description of the Related Art Conventionally, a power delay profile has been measured as a means for analyzing radio wave propagation characteristics. The power delay profile corresponds to the impulse response of the transmission path, and the radio wave output from the transmission point is reflected, diffracted, and scattered by obstacles such as buildings, and reaches the reception point at different times via various propagation paths. It shows how to do it.

Further, among some delay profile measuring methods, the method utilizing the autocorrelation characteristic of the pseudo random (PN) code can obtain a high dynamic range even at a low CN ratio (carrier power to noise power ratio). , Is commonly used.

As a measuring method utilizing the autocorrelation characteristic of the PN code, a method in which a PN code having a slightly different clock speed between the transmitting side and the receiving side is subjected to analog correlation using a multiplier and an integrator, and transmitted PN The code is roughly divided into a method of cross-correlating a reference PN code stored in advance by digital signal processing. The former is "Development of delay characteristic measuring device for millimeter wave band" at the 1994 IEICE Spring Conference B-18 (reference 1), and the latter is "2.6 GHz band micro cell multiple propagation characteristic measuring device" for electronic information communication. Academic Society A ・ P90
-86 (reference 2).

In order to improve the measurement accuracy of the delay profile, a method of directly connecting a transmitter and a receiver in advance to measure an impulse response and using a filter having a frequency characteristic opposite to the measurement result is known as "An". improved channel soun
ding technique applied towideband mobile 900 MHz p
ropagation measurements "IEEE Veh. Tec
h. Conf. , 1990 (reference 3).

Further, there is a method of performing waveform equalization after parameter estimation so that the delay profile signal measured in a state where the transmitter and the receiver are directly connected and the ideal delay profile signal are substantially the same after the correlation processing. 10-1331
It is published in Japanese Patent Publication No. 5 (Reference 4).

[0007]

By the way, in the delay profile measuring method utilizing the autocorrelation characteristic of the PN code, it is necessary to increase the code rate of the PN code in order to increase the time resolution. In this case, the transmission bandwidth becomes wider in proportion to the code rate, so the measurement system (transmitter, receiver)
Reflection and waveform distortion at the connection part due to poor frequency characteristics of the components cannot be ignored. Further, in actual measurement, it is necessary to limit the band in consideration of interference with adjacent channels, but if the band is limited more than necessary, waveform distortion will increase.

As described above, in the methods of the above-mentioned Documents 1 and 2, due to the reflection and the waveform distortion generated inside the measurement system, the resolution of the delay profile is lowered and an extra delayed wave is generated, so that the power consumption is reduced. Accurate measurement of the delay profile becomes difficult.

Therefore, it is possible to reduce the influence of reflection and waveform distortion occurring inside the measuring system on the delay profile data, and to increase the PN code rate while limiting the transmission bandwidth by limiting the bandwidth. The ability to ensure resolution is an issue in measuring highly accurate delay profiles.

The above-mentioned Documents 3 and 4 are intended for the above purpose. In the method of Document 3, the waveform equalizing filter is designed in the frequency domain, and the improvement effect is obtained by the designing method. However, there is a problem that a new distortion occurs in the measurement result even if the frequency characteristic of the filter is multiplied by the window function. Further, in Document 4, since the waveform equalization is performed on the delay profile, only the amplitude characteristic is corrected, and the phase characteristic is not corrected, so that accurate correction cannot be performed.

The present invention has been made in view of the above-mentioned problems, and it is possible to measure the delay profile of the radio wave propagation with high accuracy by utilizing the autocorrelation characteristic of the pseudo random (PN) code. An object of the present invention is to provide a method, a measuring device, and a program for delay profile measurement.

[0012]

In order to solve the above problems, the present invention employs means for solving the problems having the following features.

The invention described in claim 1 is a delay profile measuring method for measuring a delay profile of a radio wave propagation by utilizing an autocorrelation characteristic of a PN code, in a state where a transmitter and a receiver are directly connected, or a single unit. The waveform equalization is performed for each of the I axis and the Q axis of the received signal based on the ideal PN code and the PN code received while transmitting and receiving only in the propagation path.

The term "single propagation path" means that when a radio wave is transmitted and received in a certain space, of the radio waves output from the transmitting side, the propagation path of the received radio wave is limited to a single propagation path. This is the case, for example, when only direct waves are received. Moreover, when obtaining a single propagation path, an open site or an anechoic chamber is used.

According to the invention of claim 1, the I axis and the Q axis
Since the waveform equalization is performed on the axis data, the amplitude and the phase can be corrected with high accuracy. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy.

According to a second aspect of the present invention, the coefficient of the waveform equalizer used for the waveform equalization is such that the mean square error between the waveform of the PN code and the waveform of the ideal PN code is minimized. It is set to.

According to the second aspect of the present invention, it is possible to reduce the influence of the reflection or waveform distortion occurring inside the measurement system on the delay profile, and further, in the present invention, when the frequency band is limited on the transmitting side. Sufficient time resolution can be obtained by performing waveform equalization. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy.

According to a third aspect of the present invention, in the delay profile measuring apparatus for measuring the delay profile of radio wave propagation by utilizing the autocorrelation characteristic of the PN code, the demodulating means for demodulating each of the I axis and the Q axis. An AD conversion means for performing AD conversion, a waveform equalization means for performing waveform equalization,
The waveform equalizer has a processor for performing a calculation process such as calculation of a delay profile and a storage for storing an ideal PN code, and the waveform equalizer has a transmitter and a receiver directly connected to each other, or has a single propagation. It is characterized in that waveform equalization is performed for each of the I-axis and the Q-axis of the received signal based on the ideal PN code and the PN code received in the state of transmitting and receiving only through the path.

According to the invention of claim 3, the I axis and the Q axis
Since the waveform equalization is performed on the axis data, the amplitude and the phase can be corrected with high accuracy. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy.

According to a fourth aspect of the present invention, the coefficient of the waveform equalizer used in the waveform equalizing means has a minimum mean square error between the waveform of the PN code and the waveform of the ideal PN code. Is set as follows.

According to the fourth aspect of the present invention, the influence of the reflection or waveform distortion generated inside the measurement system on the delay profile can be reduced, and further, when the frequency band is limited on the transmitting side, the present invention can be applied. Sufficient time resolution can be obtained by performing waveform equalization. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy.

The invention described in claim 5 is characterized in that the PN code is band-limited and transmitted, and is received by the receiver.

According to the invention described in claim 5, the delay profile in various transmission bandwidths and PN code rates can be measured with high accuracy.

According to a sixth aspect of the present invention, there is provided a delay profile measuring program for causing a computer to execute a process of measuring a delay profile of radio wave propagation by utilizing an autocorrelation characteristic of a PN code. The computer is made to perform waveform equalization for each of the I axis and the Q axis of the received signal based on the ideal PN code and the PN code received in the directly connected state or in the state of transmitting and receiving only through a single propagation path.

According to the invention of claim 6, the I axis and the Q axis
Since the waveform equalization is performed on the axis data, the amplitude and the phase can be corrected with high accuracy. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy. In addition, since it is realized by software, it is possible to easily change the calculation parameter related to the delay profile measurement. Further, by using the program, each component of the delay profile measuring device can be easily controlled.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention deals with a reduction in time resolution in the conventional method and a delayed wave generated inside a measurement system, and therefore, a PN code of a digitized I (in-phase component) Q (quadrature component) demodulation output. On the other hand, the main object is to improve the measurement accuracy of the delay profile of radio wave propagation by performing cross-correlation calculation with an ideal PN code after waveform equalization by signal processing.

Now, the principle of the present invention will be described.

Ideally, when the PN code received with the transmitter and the receiver directly connected, or in the state of transmitting and receiving with only a single propagation path in an open site or an anechoic chamber is not affected by the measurement system. PN code (ideal PN code) waveform (hereinafter referred to as desired signal). here,
A PN that is affected by the inside of the measurement system when the transmitter and receiver are directly connected or when only a single propagation path is used for transmission and reception.
The waveform of the code is taken in, and the coefficient of the waveform equalization filter is calculated so that the mean square error between the received signal and the desired signal is minimized. That is, with respect to the coefficients of the waveform equalization filter, the normal equation of least squares estimation is solved. In this case, each expected value can be calculated by calculating the autocorrelation matrix of the received signal and the cross-correlation vector of the desired signal and the received signal over the period of the PN code. Then, the estimated amount obtained by the product of the inverse matrix of the expected value of the autocorrelation matrix of the received signal and the expected value of the cross-correlation vector becomes the optimum solution of the waveform equalization filter coefficient.

The method of obtaining the coefficients of the waveform equalization filter is not limited to the above, and for example, LMS (Least Mean)
Squares algorithm or RLS (Recursive Le)
The filter coefficients can be calculated using the ast Squares algorithm.

Calculation of the above-mentioned waveform equalization filter coefficient is performed by I
By performing waveform equalization on the I-axis and Q-axis demodulated signals before cross-correlation processing in normal measurement in advance for both the A-axis and the Q-axis, unlike the method of the above-mentioned literature 4, not only the amplitude but also the phase The included delay profile can be corrected and the accuracy of the delay profile data can be improved.

Next, a concrete embodiment of the delay profile measuring method according to the present invention will be described with reference to the drawings. The delay profile measuring device in the present invention is composed of a transmitting device and a receiving device.

FIG. 1 is a diagram showing an example of the configuration of a transmission device.

In FIG. 1, the transmitter comprises a PN code generating means 1 for generating a PN code, a band limiting filter 2 for limiting the band of the PN code, and a modulating means for modulating a carrier wave by the band limited PN code. 3, a transmitter 4 for converting an IF (intermediate frequency) signal output from the modulation means 3 into a prescribed frequency for power amplification, and a transmission antenna 5 for emitting the transmission signal to the space as a radio wave. ing.

The device configuration of the transmitting device according to the present invention is not limited to that shown in FIG. 1. For example, when the band limiting is not performed, the band limiting filter 2 can be omitted, and the band limiting filter 2 can be omitted. It may be installed between the modulation means 3 and the transmitter 4.

Next, FIG. 2 shows a first configuration example of the receiving apparatus according to the present invention.

The receiving device includes a receiving antenna 6 for taking in radio waves from space, a receiver 7 for converting an RF (high frequency) signal received by the antenna 6 into an IF signal, and an IQ demodulation means 8 for in-phase and quadrature detection of the IF signal. And AD conversion means 9 for converting an analog signal into a digital signal, and a signal processing section 10 for calculating a delay profile by performing cross-correlation between waveform equalization and an ideal PN code.

FIG. 3 shows an example of a concrete device configuration of the signal processing section 10.

The signal processing unit 10 shown in FIG. 3 is a waveform equalizer (waveform equalizer) 11 for performing waveform equalization, and an arithmetic processing unit for calculating waveform equalization coefficients, cross-correlation, and delay profile. 12 and storage means 13 for storing the ideal PN code
And are configured to include.

Here, the flow of processing of the receiving device in measuring the delay profile will be described using a flowchart. Note that the configurations of the transmitting device and the receiving device are the same as those in FIGS. 1 and 2 for ease of explanation.

FIG. 4 is a flow chart showing an example of the operation of the receiving apparatus according to the present invention.

First, as a preprocessing, the waveform equalization filter coefficient is calculated depending on the state where the transmitter 4 and the receiver 7 are directly connected or the state where transmission / reception is performed only through a single propagation path (S).
1). (Details will be described later.) After the processing of S1 is completed, the power delay profile is measured by transmitting and receiving radio waves in the propagation environment to be measured, according to the procedure of S2 to S5.

First, the signal transmitted from the transmitter is received by the receiver 7 having the antenna 6, and is digitally converted by the IQ demodulation means 8 and the AD conversion means 9 for each of the I axis and the Q axis to be digitized. The demodulated signal is taken into the signal processing unit 10 (S2).

The received signal sequence X (n) = [X
_{n, 0}, X_{n, 1}・ ・ ・ ・ ・ ・ X_{n, N -1}]^TAgainst
And the filter coefficient h = [h calculated in S1₀, H₁・ ・ ・
.., h _N-1]^TWaveform equalization (y (n) = X
^T(N) h) is performed (S3). Note that N is the waveform equalization
The number of filter taps, T, represents the transpose of the matrix. Processing of S3
After the end of, the data after waveform equalization and the ideal PN code
Correlation is performed (S4).

Here, the processing from S1 to S4 is performed on the I-axis.
Repeat for each Q axis. This makes it possible to obtain a complex delay profile.

Next, the power delay profile K (τ) = {k is calculated by calculating the sum of squares of the cross-correlation results k _i (τ) and k _q (τ) calculated for each of the I-axis and the Q-axis.
_i (τ)} ² + {k _q (τ)} ² can be obtained.
Also, the phase θ of the delayed wave can be obtained at the same time (θ
_{(Τ) = arctan {k q} (τ) / k i (τ)}).
Note that τ represents the delay time of radio wave propagation.

Next, FIG. 5 shows an example of the flow of the calculation processing from S3 to S5 described above. In order to distinguish the I-axis and the Q-axis, X (n) and h have subscripts i (I-axis) and q, respectively.
(Q axis) is used. As shown in FIG. 5, high-precision power can be obtained by performing cross-correlation using the ideal PN code after performing waveform equalization by the waveform equalization filter coefficient on the received signal series on each of the I-axis and the Q-axis. Delay profile data can be generated.

The generated power delay profile data can be easily viewed on the display device (section) or I
It can be recorded in a recording device together with the axis and Q axis data. Further, in the respective operations in S1 to S5, each device (means) can be controlled by the delay profile measuring program provided in the receiving device,
Moreover, the change of the calculation parameter can be easily realized.

Next, a specific operation of S1 (calculation of waveform equalization filter coefficient) will be described using a flowchart.

FIG. 6 is a flowchart showing an example of the operation of calculating the waveform equalization filter coefficient.

In FIG. 6, the PN code transmitted in a state in which the transmitter 4 and the receiver 7 are directly connected or in a state of transmitting and receiving only through a single propagation path is taken into the signal processing unit 10 (S).
11). Next, the acquired PN code and the ideal PN code are cross-correlated (S12). After S12 ends, a desired signal sequence is created from the ideal PN code sequence (S13).

Here, how the desired signal sequence is generated in S13 will be described with reference to the drawings.

FIG. 7 is a diagram showing an example of a method of generating a desired signal sequence. In FIG. 7, first, the ideal P for two cycles is
From the N code sequence, a sequence further shifted by L from the sequence having the strongest correlation with the captured data acquired in S12 is extracted, and its amplitude is set as the peak value of the cross-correlation performed in process S12, and the desired signal sequence { d ₀ , d ₁ , ...,
d _M-1 } is generated. However, N represents the number of taps of the waveform equalization filter, and M represents the number of data for one period of the PN code. Further, L is an integer in the range of 0 to N-1,
When = N / 2, waveform equalization can be performed evenly from past and future data at a certain time of the signal, which is efficient.

Next, the reception signal series X (n) is created (S14). Note that the received signal series X (n) created in the same manner is also used in S3. Here, how the reception signal sequence is generated in S14 will be described with reference to the drawings.

FIG. 8 is a diagram showing an example of a method of generating a received signal sequence. In FIG. 8, first, N pieces of data are sequentially extracted from the beginning of the (M + N−1) pieces of captured data series by shifting them one by one, and the data at the new time is rearranged so as to have a small number and received. Signal sequence X (n) = [X _{n, 0} , X _{n, 1} , ..., X _{n, N
-1} ] ^T.

Since the PN code is a periodic signal, when all the delayed waves are included in the time of one cycle (normally, the PN code generation formula is determined so that it does), the data for one cycle. It is also possible to obtain (M + N-1) data series by adding N-1 data from the beginning to the end.

Next, the expected value R of the autocorrelation matrix of the received signal sequence is calculated by the following equation (1).

[0057]

[Equation 1] Further, the expected value P of the cross-correlation vector between the received signal sequence and the desired signal is calculated by the following equation (2).

[0058]

[Equation 2] After the processing of S15 is completed, the optimum coefficient of the waveform equalization filter is calculated (S16). The optimum coefficient is obtained by h = R ⁻¹ P. However, R ⁻¹ represents the inverse matrix of R.

Here, an example of the flow of the calculation operation from S13 to S16 will be described with reference to FIG. In addition, I axis and Q
In order to clearly distinguish the axes, X (n), h, d, R,
For i and P, i (I axis) and q (Q axis) are used as subscripts.

The expected value (R) of the autocorrelation matrix of the received signal series is determined by the received signal series of the I axis and the Q axis and the desired signal series.
_i , R _q ) and the expected value (P _i , P _q ) of the cross-correlation vector between the received signal sequence and the desired signal can be calculated to obtain the optimum value of the waveform equalization filter coefficient.

The cross-correlation in S4 and S12 is
As shown in FIG. 10, for each delay time τ, one cycle
For each combination of the data series and the ideal PN series
Correlation processing is performed. Here, the correlation process is the data series
To {T₀, T₁・ ・ ・, T _M-1}, The theory of delay time τ
Thought PN sequence is {U_{τ, 0}, U_{τ, 1}, ・ ・ ・, U_τ,
M-1}, The delay time τ can be expressed by the following equation (3).
Calculate with.

[0062]

[Equation 3] In the case of S4, the data sequence referred to here is the PN sequence {y after the waveform equalization of the received PN sequence acquired.
(0), y (1), ..., y (M-1)}, and S
Reference numeral 12 represents a reception PN sequence that is not subjected to waveform equalization when it is received in a state where the transmitter and the receiver are directly connected to each other or a state where transmission and reception are performed only through a single propagation path. If the propagation environment does not change, the reception P for one cycle
The N series is obtained by averaging a plurality of cycles to obtain the SN ratio (S
/ N) can be improved, and the dynamic range of the delay profile can be improved.

By the processing described above, highly accurate power delay profile data can be generated.

The receiving apparatus according to the present invention is not limited to the above, and for example, a digital IQ is provided in the signal processing unit.
By including the modulation means, the contents of the device configuration can be changed. Here, the above content will be described as a second configuration example of the receiving apparatus according to the present invention with reference to FIG.

The receiver shown in FIG. 11 has a receiving antenna 6 for taking in radio waves from space, a receiver 7 for converting an RF signal received by the antenna into an IF signal, an AD converting means 14 for digitizing the IF signal, and a digital signal. It is configured to include a signal processing unit 15 that performs IQ demodulation, waveform equalization processing, and cross-correlation with an ideal PN code to generate a delay profile.

A specific device configuration example of the signal processing unit 15 described above will be described with reference to the drawings.

FIG. 12 is a diagram showing an example of a concrete device configuration of the signal processing unit in the second embodiment.

In FIG. 12, the signal processing section 15 includes a digital IQ demodulation means 16 for performing in-phase and quadrature detection by signal processing, a waveform equalization means 11 for waveform equalization, calculation of waveform equalization coefficients, and cross correlation. , And a calculation processing means 12 for calculating a delay profile, and a storage means 13 for storing an ideal PN code.

By using the receiving apparatus shown in FIGS. 11 and 12, it is possible to measure the delay profile with the same accuracy as in the first embodiment.

Next, the calculation result of the delay profile in the present invention will be described with reference to the drawings. It should be noted that the following are all calculation results in the situation where only direct waves are received.

In FIG. 13, the PN code of 500 Mbps is 1
It is a figure which shows the calculation result of delay profile measurement by the presence or absence of waveform equalization at the time of carrying out band limitation by RF bandwidth of GHz. In addition, in FIG. 14, a 1 Gbps PN code is set to 1 GHz.
FIG. 6 is a diagram showing calculation results of delay profile measurement depending on the presence or absence of waveform equalization when the band is limited by the RF bandwidth of FIG. 13 and 14, (a) shows the calculation result when the waveform equalization of the present invention is not applied, and (b) shows the calculation result when the waveform equalization of the present invention is applied.

FIG. 15 shows the PN of FIGS. 13 and 14.
It is a figure which shows the spectrum of the carrier wave modulated with the code | symbol. 15A shows the spectrum of the carrier in FIG. 13, and FIG. 15B shows the spectrum of the carrier in FIG.

As shown in FIG. 15A, when the band is limited so that all the main lobes of the PN code are transmitted, the measurement is performed when the waveform equalization according to the present invention is performed as shown in FIG. It can be seen that the reflected waves generated inside the system are suppressed. In addition, as shown in FIG.
If the band is severely limited so that 1/2 of the main lobe of the code is transmitted, as shown in FIG.
In FIG. 14B, the width of the correlation peak is widened and the resolution is reduced in FIG. 14A, but it is improved in FIG. 14B.
It can be seen that sufficient time resolution is obtained.

By carrying out the waveform equalization according to the present invention, it can be seen in FIGS. 13 and 14 that the dynamic range near the correlation peak is improved by 10 dB or more.

13 and 14 are the same at 1 GHz.
However, the time resolution defined by the level 20 dB lower than the correlation peak is 4 ns in FIG.
It can be seen that it is 2 ns in (b). Therefore, it is shown that the application of the present invention can increase the time resolution about twice.

According to the present invention, the transmitted pseudo-random (PN) code has a means for calculating a delay profile by waveform correlation and then cross-correlation with an ideal PN code. By setting the coefficient of the waveform equalizer so that the mean square error between the waveform of the PN code and the waveform of the ideal PN code received in the state of being directly connected or transmitting / receiving only through a single propagation path is minimized. The influence of reflection or waveform distortion occurring inside the measurement system on the delay profile can be reduced, and even if the frequency band is limited on the transmission side, waveform equalization according to the present invention provides sufficient time resolution. Obtainable.

In particular, when the band limitation is set wider than the main lobe width of the PN code, the influence inside the measurement system can be removed very efficiently. In addition, the band limit is PN
Even when the width is set narrower than the main lobe width of the code, it is possible to secure sufficient measurement accuracy without lowering the time resolution. Since this waveform equalization minimizes the mean square error of the time axis signal, new distortion does not occur in the result of waveform equalization, and measurement accuracy is improved compared to the method of designing in the frequency domain. Can be improved.

Further, since the waveform equalization is performed on the I-axis and Q-axis data before the calculation of the delay profile, the amplitude and phase can be corrected with high accuracy. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy.

[0079]

As described above, according to the present invention, it is possible to reduce the influence of internal reflection, waveform distortion, etc. in the measurement system (transmitting device, receiving device) on the delay profile from the received signal received, and further Even if the frequency band is limited on the transmitting side, sufficient time resolution can be obtained by the waveform equalization function. Therefore, it is possible to measure the delay profile of radio wave propagation with high accuracy.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration example of a transmission device.

FIG. 2 is a diagram showing a first configuration example of a receiving device according to the present invention.

FIG. 3 is a diagram showing a configuration example of a signal processing unit in the first embodiment.

FIG. 4 is a flowchart showing an example of the operation of the receiving device according to the present invention.

FIG. 5 is a diagram showing an example of the flow of calculation processing from S3 to S5.

FIG. 6 is a flowchart showing an example of a coefficient calculation operation of a waveform equalization filter.

FIG. 7 is a diagram showing an example of a method of generating a desired signal sequence.

FIG. 8 is a diagram showing an example of a method of generating a received signal sequence.

FIG. 9 is a diagram showing an example of the flow of calculation operations from S13 to S16.

FIG. 10 is a diagram illustrating an example of a combination of a delay time and a data sequence / ideal PN code that are mutually correlated.

FIG. 11 is a diagram showing a second configuration example of the receiving device according to the present invention.

FIG. 12 is a diagram illustrating an example of a specific device configuration of a signal processing unit in a second configuration example.

FIG. 13: PN code of 500 Mbps and RF of 1 GHz
It is a figure which shows the calculation result of delay profile measurement by the presence or absence of waveform equalization at the time of carrying out band limitation by the bandwidth.

FIG. 14 is a diagram showing calculation results of delay profile measurement depending on the presence / absence of waveform equalization when a 1 Gbps PN code is band-limited with an RF bandwidth of 1 GHz.

FIG. 15 is a diagram showing a spectrum example of a carrier modulated by the PN code of FIGS. 13 and 14;

[Explanation of symbols]

1 PN code generating means 2 Band limiting filter 3 Modulation means 4 transmitter 5,6 antenna 7 receiver 8 IQ demodulation means 9,14 AD conversion means 10, 15 Signal processing unit 11 Waveform equalization means 12 Arithmetic processing means 13 storage means 16 Digital IQ demodulation means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroyuki Furuta             1-10-11 Kinuta, Setagaya-ku, Tokyo, Japan             Broadcasting Association Broadcast Technology Institute F term (reference) 5K046 AA05 EE06 EE37 EE56 EF03                       EF11

Claims (6)

[Claims] 1. A delay profile measuring method for measuring a delay profile of radio wave propagation by utilizing an autocorrelation characteristic of a PN code, wherein a transmitter and a receiver are directly connected to each other or a single propagation path is used for transmission and reception. PN code received in and the ideal PN
A delay profile measuring method characterized by performing waveform equalization on each of the I axis and the Q axis of a received signal based on the code. 2. The coefficient of the waveform equalizer used for the waveform equalization is an average of 2 of the waveform of the PN code and the waveform of the ideal PN code.
The delay profile measuring method according to claim 1, wherein the multiplication error is set to be a minimum. 3. A delay profile measuring device for measuring a delay profile of radio wave propagation by utilizing an autocorrelation characteristic of a PN code, a demodulation means for demodulating each of an I axis and a Q axis, and A
An AD converting means for performing D conversion, a waveform equalizing means for performing waveform equalization, an arithmetic processing means for performing arithmetic processing in delay profile calculation and the like, and a storage means for storing an ideal PN code. The equalizer is a state where the transmitter and the receiver are directly connected,
Alternatively, based on the PN code received in the state of transmitting and receiving only through a single propagation path and the ideal PN code, the I of the received signal is
A delay profile measuring device characterized by performing waveform equalization on each of the axis and the Q axis. 4. The coefficient of the waveform equalizer used in the waveform equalizing means has an average of 2 between the waveform of the PN code and the waveform of the ideal PN code.
The delay profile measuring device according to claim 3, wherein the multiplication error is set to be a minimum. 5. The delay profile measuring apparatus according to claim 3, wherein the PN code is band-limited and transmitted, and is received by the receiver. 6. A delay profile measuring program for causing a computer to execute a process of measuring a delay profile of radio wave propagation by utilizing an autocorrelation characteristic of a PN code, in a state where a transmitter and a receiver are directly connected, or a single The ideal PN and the PN code received while transmitting and receiving only on the propagation path
A delay profile measuring program for causing a computer to perform waveform equalization for each of the I axis and the Q axis of a received signal based on the code.