JPH08223108A - Fading pitch estimating device - Google Patents

Abstract

PURPOSE: To improve the detection precision of the fading pitch with respect to the fading pitch estimating device which detects the reception level variation of a reception signal to estimate the fading pitch in a mobile communication system. CONSTITUTION: When the fading pitch gets higher, the difference of the reception level is larger, and consequently, the integrated value exceeds a prescribed set value earlier. That is, the time and the fading pitch have correlations that the higher the fading pitch becomes the smaller the time value becomes. The table of correlations between the fading pitch value and the time value is preliminarily obtained by experiment, and a fading pitch detection part 17 uses this correlation table to convert the time value obtained by an integrated time detection part 16 to the fading pitch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fading pitch estimating device in a mobile communication system, and more particularly to a fading pitch estimating device for detecting a received level fluctuation of a received signal to estimate a fading pitch. In the present specification, the "fading pitch" means a fading frequency.

[0002] In recent years, the demand for mobile communication systems has increased, and many radio frequencies are inevitably required.
However, there are limits to the radio frequencies that can be used. Therefore, introduction of dynamic channel allocation control or the like is being considered in order to effectively use the radio frequency. In dynamic channel allocation control, it is pointed out that call movement speed information plays an important role, and it is necessary to obtain the call movement speed, that is, the movement speed of the mobile station. The moving speed of the mobile station can be easily calculated by detecting the fading pitch.

[0003]

2. Description of the Related Art Conventionally, as a fading pitch estimating device in a mobile communication system, there is, for example, a "moving speed detecting device in a mobile communication system" (International Application No. PCT-JP93-01714) by the applicant. In such a device, as shown in FIG. 11, first, the receiver 101 receives a transmission radio wave, and the reception level of the reception signal is detected by the level detection unit 10 for each timing signal of a predetermined cycle T.
2 is detected, and the A / D converter 103 converts it into a digital value for sampling. Based on the sampled reception level, a difference between the reception level sampled this time and the reception level sampled last time is obtained at each sampling by the difference detection unit 104 having a built-in storage device. The comparison unit 105 compares this difference with a threshold value, and causes the counter 106 to count up when the difference is larger than the threshold value. The counter 106 counts this for a predetermined time, and the conversion unit 107 converts the count value into a fading pitch and further into the moving speed of the mobile station. The conversion unit 107 experimentally obtains and stores beforehand a correlation table between the count value and the fading pitch, and performs conversion by referring to the correlation table. Since the fading pitch f _d and the moving speed v of the mobile station have a relationship represented by the following formula, the moving speed of the mobile station is calculated based on this formula.

V = f _d × λ (λ is the wavelength of the received signal)

[0005]

However, as described above, the comparison unit 105 compares the difference obtained by the difference detection unit 104 with a threshold value, for example, 3 dBμ, and when the difference is larger than the threshold value, counts only one in the counter 106. Up is performed, and if the difference is larger than the threshold value, uniformly,
The counter 106 is made to count up only one. That is, even if the difference is 5 dBμ, or 3d
The treatment is the same even if it is slightly larger than Bμ. Therefore, there is a problem that the detection accuracy is low at the fading pitch detected by such a device.

Further, the value of the reception level on which the difference is calculated by the difference detection unit 104 may be very small, and the reception level in such a case is often buried in noise. However, in the past, even when the reception level was very small, the difference was calculated based on such reception level, so the calculated difference was not always a reliable value, and therefore, it was detected based on such difference. There is a problem that the reliability of fading pitch is low.

Further, there is a phenomenon that the count value obtained by the counter 106 varies depending on the magnitude of the received electric field strength, even though the fading pitch value is the same, which is a conventional case in which the received electric field strength is not taken into consideration. The fading pitch detection has a problem that the detection accuracy cannot be increased.

Further, in the above-mentioned conventional apparatus, the fading pitch detection accuracy may be lowered depending on the fading pitch area, and the area with low fading pitch changes according to the size of the predetermined cycle T of sampling. The phenomenon occurs.

FIG. 12 shows an example of a correlation table between the count value and fading pitch used in the conversion section 107. The curve 108 has a predetermined sampling period T of 20.
The curve 109 shows a correlation table when the sampling period T is 10 ms. In the figure, the fading pitch is represented by a logarithmic memory.

As can be seen from this figure, the curve 108 has a high fading pitch region (about 10 Hz or more).
Therefore, the fading pitch does not change so much despite the change in the count value, resulting in a large detection error. Further, the curve 109 becomes flat in a region where the fading pitch is low (about 10 Hz or less), and the detection error similarly increases. That is, there is a problem in that it is not possible to set a single predetermined period T that can maintain high fading pitch detection accuracy over a wide fading pitch region.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fading pitch estimation device which improves the accuracy of fading pitch detection.

[0012]

In order to achieve the above object, the present invention has a sampling means (12, 13) for sampling the reception level of a reception signal at a predetermined cycle as shown in FIG. The difference calculating means (14, 15) for calculating the difference between the reception levels, the integrating means (16) for integrating the calculated differences, and the value obtained by the integration until the value exceeds a predetermined value. There is provided a fading pitch estimating device comprising a time measuring means (16) for obtaining time and a fading pitch estimating means (17) for estimating a fading pitch based on the obtained time.

[0013]

When the fading pitch becomes higher, the difference between the reception levels becomes larger, and therefore the integrated value quickly exceeds the predetermined set value. Therefore, the higher the fading pitch, the smaller the above time value becomes. Between time and fading pitch.

Therefore, a correlation table between the fading pitch value and the time value is obtained in advance by an experiment, and the fading pitch estimating means (17) uses the correlation table to obtain the time measuring means (16). Try to convert time values to fading pitch.

Since this time value is measured based on the difference, this time value slightly changes according to the magnitude of the difference, and therefore the fading pitch can be detected with high accuracy. Becomes

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a fading pitch estimating apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In the figure, the receiver 11 receives a transmission radio wave, the level detection unit 12 detects the reception level of the reception signal based on a timing signal of a predetermined cycle, and the A / D converter 13 converts the received signal into a digital value to perform sampling. Done. The reception level sampled last time is held in the storage unit 14 for each sampling, and the difference detection unit 15 calculates the difference between the reception level sampled this time and the reception level sampled last time for each sampling. The calculated value is output to the integrated time detection unit 16. The integrated time detection unit 16 integrates (accumulates) the differences that are sequentially sent, and measures the time until the integrated value exceeds a predetermined set value.

The higher the fading pitch, the larger the difference between the reception levels, and therefore the integrated value quickly exceeds a predetermined set value. Therefore, the higher the fading pitch, the smaller the above time value becomes. Between time and fading pitch.

Therefore, an experiment is conducted in advance to obtain a correlation table between the fading pitch value and the time value, and the fading pitch detection unit 17 uses the correlation table to obtain the time value obtained by the integrated time detection unit 16. To be converted to fading pitch. Since this time value is timed based on the difference, the time value slightly changes according to the magnitude of the difference.
Therefore, the fading pitch can be detected with high accuracy.

Next, a second embodiment of the present invention will be described. FIG. 2 is a block diagram showing the configuration of the second embodiment. Since the configuration of the second embodiment is basically the same as that of the first embodiment, the same parts are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

In the second embodiment, the difference between the reception level sampled this time and the reception level sampled last time is sent from the difference detection unit 15 to the comparison unit 18 at every sampling, and the comparison unit 18 sends the difference. Each obtained difference is compared with the threshold value sent from the threshold value output unit 19. Then, only the difference equal to or larger than the threshold value is sent to the integrated time detection unit 16. The integrated time detection unit 16 integrates (accumulates) the differences sequentially sent from the comparison unit 18, and measures the time until the integrated value exceeds a predetermined set value.

That is, when the fading pitch is high, the number of differences that are equal to or greater than the threshold and are sent to the integration time detection unit 16 is large, and when the fading pitch is low, the number of differences that are equal to or greater than the threshold is small. Compared with the first embodiment, the difference between the time value when the fading pitch is high and the time value when the fading pitch is low appears clearly, and the fading pitch can be detected with higher accuracy.

Next, a third embodiment of the present invention will be described. FIG. 3 is a block diagram showing the configuration of the third embodiment. Since the configuration of the third embodiment is basically the same as that of the first embodiment, the same parts are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

In the third embodiment, the foot level level output unit 22 is connected to the difference detection unit 21 to supply the foot level. The foot level is set to a value slightly higher than the noise level included in the reception level. The difference detection unit 21 compares the sampled reception level with the foot level, and when both the previous and current sampling reception levels are equal to or higher than the foot level, the reception level sampled this time and the sampling level last sampled. The difference with the received level is obtained, and the difference is sent to the fading pitch detection processing unit 23. The fading pitch detection processing unit 23 has the same configuration as the integration time detection unit 16 and the fading pitch detection unit 17 of the first embodiment, performs the same operation as in the case of the first embodiment, and sequentially sends each difference. Is accumulated (accumulated), the time until this accumulated value exceeds a predetermined set value is measured, and this time value is converted into a fading pitch using a correlation table. As a result, more accurate fading pitch detection is realized by using a reliable difference that is not disturbed by noise.

FIG. 4 is a flow chart showing the procedure of processing performed in the third embodiment. Hereinafter, description will be given along the steps shown in the drawing. [S1] The control variable n of this processing is set to 0.

[S2] The level detection unit 12 and the A / D converter 13 perform sampling at the cycle T, and the sampled reception level is sent to the difference detection unit 21 at every sampling.

[S3] The reception level R (t + nT) sampled last time is compared with the foot level. As a result, if the reception level R (t + nT) is equal to or higher than the foot level, the processing proceeds to step S4, and if it is lower than the foot level, the processing proceeds to step S6.

[S4] The reception level R {t + (n + 1) T} sampled this time is compared with the foot level. As a result, if the reception level R {t + (n + 1) T} is equal to or higher than the foot level, the processing proceeds to step S5, and if it is lower than the foot level, the processing proceeds to step S6.

[S5] The difference between the reception levels sampled last time and this time is calculated and sent to the fading pitch detection processing section 23. Fading pitch detection processing unit 23
Adds (cumulatively) each difference sent sequentially.

[S6] Fading pitch detection processing unit 2
3 determines whether or not the integrated value integrated in step S5 exceeds a predetermined set value, and if it exceeds, the time until it is exceeded is obtained, and this time value is used as the fading pitch using the correlation table. Along with the conversion, a reset signal is output to the difference detection unit 21 to end this processing, and if not exceeded, the process proceeds to step S7. Upon receiving the reset signal, the difference detection unit 21 stops the difference detection.

[S7] The control variable n is increased by 1 to prepare for the next difference calculation. As described above, since both the previous sampling reception level and the current sampling reception level used for the difference calculation in step S5 are equal to or higher than the foot level, these reception levels are significant values clearly distinguished from noise. Can be considered. Since the difference is detected based on such a reception level, the difference becomes a reliable value.

The difference detector 21 may perform the difference detection shown in FIG. 5 instead of the difference detection shown in FIG. FIG. 5 is a flowchart showing the procedure of another difference detection process that can be performed in the configuration of the third embodiment. In this flowchart, steps S11 to S11
S12 and steps S15 to S17 are steps S1 to S2 and steps S5 to S in the flowchart of FIG.
7 and 7, respectively. Therefore, description of the same steps will be omitted, and only different steps S13 and S14 will be described.

[S13] The previously sampled reception level R (t + nT) is compared with the foot level. As a result, if the reception level R (t + nT) is equal to or higher than the foot level, the process proceeds to step S15, and if it is lower than the foot level, the process proceeds to step S14.

[S14] The reception level R {t + (n + 1) T} sampled this time is compared with the foot level. As a result, if the reception level R {t + (n + 1) T} is equal to or higher than the foot level, the processing proceeds to step S15, and if it is lower than the foot level, the processing proceeds to step S16.

That is, in this difference detection process, the difference is calculated if at least one of the reception levels sampled last time and this time is equal to or higher than the foothold level.

Next, a fourth embodiment of the present invention will be described. FIG. 6 is a block diagram showing the configuration of the fourth embodiment. Since the configuration of the fourth embodiment is basically the same as that of the first embodiment, the same parts are designated by the same reference numerals, the description thereof will be omitted, and only different parts will be described.

In the fourth embodiment, the A / D converter 13
The sampling value of the reception level output from the adder 2
5 and the division unit 26, the reception levels are averaged here, and the average reception level is sent to the fading pitch detection unit 27.

In the fading pitch detecting section 27, a plurality of correlation tables between the time value obtained by the integrated time detecting section 16 and the fading pitch are prepared in advance for each received electric field strength and stored based on experiments.

The fading pitch detector 27 detects the fading pitch based on the time value sent from the integrated time detector 16 and the average reception level sent from the divider 26. That is, the correlation table corresponding to the average reception level sent from the division unit 26 is selected from the plurality of correlation tables, and the time value sent from the integration time detection unit 16 is converted into a fading pitch.

As described above, the fading pitch is detected in consideration of the average reception level. Therefore, as compared with the conventional device for converting the fading pitch using the same correlation table regardless of the received electric field strength, The detection accuracy of fading pitch is improved.

Next, a fifth embodiment of the present invention will be described. FIG. 7 is a block diagram showing the configuration of the fifth embodiment. Since the configuration of the fifth embodiment is basically the same as that of the first embodiment, the same components are designated by the same reference numerals, and the description thereof will be omitted. Only different portions will be described.

In the fifth embodiment, the 20 ms timer 30 and the 10 ms timer 31 are connected to the level detecting section 12, and the timing signals of the cycle of 20 ms and the cycle of 10 ms are supplied to the level detecting section 12, respectively. The level detection unit 12 detects the reception level of the reception signal based on these timing signals of 20 ms and 10 ms, and the detected analog values are converted into digital values by the A / D converter 13, respectively, and sampling is completed. To do.

Each reception level sampled based on the 20 ms timing signal is sent to the 20 ms difference detection section 32 and the storage section 33, and each reception level sampled based on the 10 ms timing signal is sent to the 10 ms difference detection section 34 and the storage section 35. Sent. The reception level sampled last time is held in the storage unit 33 and the storage unit 35 each time.

The 20 ms difference detection unit 32 obtains the difference between the reception level sampled this time and the reception level previously sampled and stored based on the 20 ms timing signal for each sampling. Similarly, the 10 ms difference detection unit 34 obtains the difference between the reception level sampled this time based on the 10 ms timing signal and the reception level previously sampled and stored for each sampling.

The 20 ms difference detector 32 sends the obtained differences to the integrated time detector 36. The integrated time detection unit 36 integrates (accumulates) the differences that are sequentially sent, and measures the time until the integrated value exceeds a predetermined set value.
The measured time value is the fading pitch detection unit 38.
Output to Similarly, the 10 ms difference detection unit 34 also sends the obtained difference to the integration time detection unit 37. The integrated time detection unit 37 integrates (accumulates) the differences that are sequentially sent, and measures the time until the integrated value exceeds a predetermined set value. The counted time value is output to the fading pitch detector 38.

The fading pitch detector 38 compares the time value sent from the integrated time detector 36 with a predetermined value, and if the time value is less than the predetermined value, the time value sent from the integrated time detector 36 is determined. , 20m corresponding to the curve 108 in FIG.
The fading pitch is converted using a correlation curve based on a timing signal of s period. If the time value is greater than or equal to the predetermined value, the time value sent from the integrated time detection unit 37 is
A fading pitch is converted using a correlation curve based on a timing signal having a period of 10 ms, which corresponds to the curve 109 in FIG. The correlation curve between the time value and the fading pitch is also a curve corresponding to the curves 108 and 109 shown in FIG.

As described above, in this fading pitch conversion process, for example, in FIG. 12, the left side portion of the curve 108 from the point P1 and the right side portion of the curve 109 from the point P2 are used as a correlation table. Therefore, since there is no flat portion which is a fading pitch detection error in the correlation tables used in this way, the fading pitch can be detected with high accuracy.

Next, a sixth embodiment of the present invention will be described. FIG. 8 is a block diagram showing the configuration of the sixth embodiment. Since the configuration of the sixth embodiment is basically the same as the configuration of the first embodiment, the same parts are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

In the sixth embodiment, the footfall level output unit 41 is connected to the difference detection unit 40 to supply the footfall level. The foot level is set to a value slightly higher than the noise level included in the reception level. The difference detection unit 40 compares the sampled reception level with the foot level, and when both the previous and current sampling reception levels are equal to or higher than the foot level, the reception level sampled this time and the sampling level last sampled. The difference with the reception level is calculated, and the difference is compared with a predetermined threshold value (for example, 3 dBμ). When the difference is equal to or larger than the predetermined threshold value, the drive signal is output to the counter 42. The counter 42
It counts up each time a drive signal is input, and outputs the count value to the processing time detection unit 43.

The processing time detector 43 monitors whether or not the sent count value exceeds a predetermined set value. If the count value exceeds the predetermined set value, the time until the count value is exceeded is obtained, and this time value is used as the fading pitch detector. I will send it to 44. At the same time, a reset signal is output to the difference detection unit 40. Upon receiving the reset signal, the difference detection unit 40 stops the difference detection.

As described above, both the previous and present sampling reception levels used for the difference calculation are higher than the foot level, and therefore these reception levels are significant values clearly distinguished from noise. Can be seen. Since the difference is detected based on such a reception level, the difference becomes a reliable value. Therefore, a more accurate fading pitch detection is realized by using a reliable difference that is not disturbed by noise.

In this embodiment, the difference detector 40
However, when both the previous and current sampling reception levels are higher than the threshold level, the difference between the reception level sampled this time and the reception level sampled last time is calculated. Then, when at least one of the previous and present sampling reception levels is equal to or higher than the marginal level, the difference detecting unit 40 detects the reception level sampled this time,
You may make it obtain | require the difference with the reception level sampled last time.

Next, a seventh embodiment of the present invention will be described. FIG. 9 is a block diagram showing the configuration of the seventh embodiment. Since the configuration of the seventh embodiment is basically the same as that of the sixth embodiment, the same parts are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described.

In the seventh embodiment, the A / D converter 13
The sampling value of the reception level output from the adder 4
5 and the division unit 46, the reception levels are averaged here, and the average reception level is sent to the fading pitch detection unit 47.

In the fading pitch detecting section 47, a plurality of correlation tables between the time value obtained by the processing time detecting section 43 and the fading pitch are prepared in advance for each received electric field strength and stored based on experiments.

The fading pitch detector 47 detects the fading pitch based on the time value sent from the processing time detector 43 and the average reception level sent from the divider 46. That is, the correlation table corresponding to the average reception level sent from the division unit 46 is selected from the plurality of correlation tables, and the time value sent from the processing time detection unit 43 is converted into the fading pitch.

As described above, the fading pitch is detected in consideration of the average reception level, and accordingly, the sixth
The detection accuracy of the fading pitch is improved as compared with the apparatus which converts into the fading pitch using the same correlation table regardless of the received electric field strength as in the above embodiment.

Next, an eighth embodiment of the present invention will be described. FIG. 10 is a block diagram showing the configuration of the eighth embodiment. Since the configuration of the eighth embodiment is basically the same as that of the fifth embodiment, the same parts are designated by the same reference numerals, the description thereof will be omitted, and only different parts will be described.

In the eighth embodiment, each reception level sampled based on the 20 ms timing signal is 20 ms.
It is sent to the difference detection unit 49 and the storage unit 51, and
Each reception level sampled based on the ms timing signal is sent to the 10 ms difference detection unit 54 and the storage unit 56. The reception levels sampled last time are respectively retained in the storage unit 51 and the storage unit 56.

The 20 ms difference detecting section 49 is connected to the foot level level output section 50 to supply the foot level. The foot level is set to a value slightly higher than the noise level included in the reception level. The 20 ms difference detection unit 49 compares each reception level sampled on the basis of the 20 ms timing signal with the foot level, and when both the previous and current sampling reception levels are equal to or higher than the foot level, it is sampled this time. The difference between the reception level and the previously sampled reception level is calculated, and this difference is compared with a predetermined threshold value (for example, 3 dBμ).
Output to 2. The counter 52 counts up each time a drive signal is input, and the count value is counted by the processing time detection unit 53.
Output to.

The processing time detector 53 monitors whether the sent count value exceeds a predetermined set value, and if it exceeds, obtains the time until the count value is exceeded, and determines the time value as the fading pitch detector. In addition to sending to 59, the reset signal is output to the 20 ms difference detection unit 49. 20m
Upon receiving the reset signal, the s difference detection unit 49 stops the difference detection.

Similarly, the 10 ms difference detector 54 is connected to the foot level output unit 55 to supply the foot level. The 10 ms difference detection unit 54 compares each reception level sampled on the basis of the 10 ms timing signal with the foot level, and when both the previous and current sampling reception levels are equal to or higher than the foot level, the 10 ms difference detection section 54 is sampled this time. The difference between the reception level and the previously sampled reception level is obtained, this difference is compared with a predetermined threshold value (for example, 3 dBμ), and a drive signal is output to the counter 57 when the difference is equal to or larger than the predetermined threshold value. The counter 57
It counts up each time a drive signal is input and outputs the count value to the processing time detection unit 58.

The processing time detector 58 monitors whether the sent count value exceeds a predetermined set value, and if it exceeds, obtains the time until the count value is exceeded, and uses this time value as the fading pitch detector. In addition to being sent to 59, the reset signal is output to the 10 ms difference detection unit 54. 10m
Upon receiving the reset signal, the s-difference detecting unit 54 stops detecting the difference.

The fading pitch detector 59 compares the time value sent from the processing time detector 53 with a predetermined value, and if the time value is less than the predetermined value, the time value sent from the processing time detector 53 is determined. , 20m corresponding to the curve 108 in FIG.
The fading pitch is converted using a correlation curve based on a timing signal of s period. If the time value is greater than or equal to the predetermined value, the time value sent from the processing time detection unit 58 is
A fading pitch is converted using a correlation curve based on a timing signal having a period of 10 ms, which corresponds to the curve 109 in FIG. The correlation curve between the time value and the fading pitch is also a curve corresponding to the curves 108 and 109 shown in FIG.

As described above, in this fading pitch conversion process, for example, in FIG. 12, the left side portion of the curve 108 from the point P1 and the right side portion of the curve 109 from the point P2 are used as the correlation table. Therefore, since there is no flat portion which is a fading pitch detection error in the correlation tables used in this way, the fading pitch can be detected with high accuracy.

Further, since both the previous and present sampling reception levels used for the difference calculation are higher than the foot level, these reception levels can be regarded as significant values clearly distinguished from noise. . Since the difference is detected based on such a reception level, the difference becomes a reliable value. Therefore, a more accurate fading pitch detection is realized by using a reliable difference that is not disturbed by noise.

In the eighth embodiment, the 20 ms difference detecting section 49 and the 10 ms difference detecting section 54 are sampled this time when both the previous and current sampling reception levels are equal to or higher than the cut-off level. The difference between the reception level and the reception level sampled last time is calculated, but instead of this, 20 ms
The difference detection unit 49 and the 10 ms difference detection unit 54 determine whether the reception level sampled this time and the reception level sampled last time are present when at least one of the sampling reception levels of the previous time and this time is equal to or higher than the marginal level. You may make it obtain | require a difference.

Further, in the eighth embodiment, the foot-cutting level output sections 50, 55 are provided, but this is not always necessary, and the structure of the fifth embodiment may be adopted.

[0069]

As described above, according to the present invention, the differences between sampled reception levels are integrated and the time until the integrated value exceeds a predetermined value is calculated, or
The number of times the difference between the sampled reception levels exceeds a threshold value is counted, the time until the count value exceeds a predetermined value is obtained, and the fading pitch is estimated based on the obtained time value. This time value slightly changes depending on the magnitude of the difference, and therefore, it becomes possible to detect the fading pitch with high accuracy.

Since the fading pitch can be detected with high accuracy, the moving speed of the moving body, which is an important parameter in the mobile communication system, can be accurately estimated, and therefore, the high quality of the radio line control and the service control can be achieved. It will greatly contribute to the realization.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a second embodiment.

FIG. 3 is a block diagram showing a configuration of a third embodiment.

FIG. 4 is a flowchart showing a procedure of processing performed in a third embodiment.

FIG. 5 is a flowchart showing the procedure of another difference detection process that can be performed in the configuration of the third embodiment.

FIG. 6 is a block diagram showing a configuration of a fourth exemplary embodiment.

FIG. 7 is a block diagram showing a configuration of a fifth exemplary embodiment.

FIG. 8 is a block diagram showing a configuration of a sixth exemplary embodiment.

FIG. 9 is a block diagram showing a configuration of a seventh embodiment.

FIG. 10 is a block diagram showing a configuration of an eighth embodiment.

FIG. 11 is a configuration diagram of a conventional device.

FIG. 12 is a diagram showing an example of a correlation table between a count value and a fading pitch used in a conversion unit.

[Explanation of symbols]

11 receiver 12 level detection unit (sampling means) 13 A / D converter (sampling means) 14 storage unit (difference calculation means) 15 difference detection unit (difference calculation means) 16 integration time detection unit (integration means, time measurement means) 17 Fading pitch detection unit (fading pitch estimation means)

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Ryuji Nakamura 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Kazuo Kawabata 1015, Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor Kazuo Obuchi 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited (72) Inventor Tadao Takami 2-10-1 Toranomon, Minato-ku, Tokyo NTT Mobile Communications Network Co., Ltd. Within

Claims (12)

[Claims] 1. A fading pitch estimation device in a mobile communication system, sampling means for sampling a reception level of a reception signal at a predetermined cycle, difference calculation means for calculating a difference between the sampled reception levels, and the calculation. Integrating means for integrating each of the obtained differences, time measuring means for obtaining a time until the value obtained by the integration exceeds a predetermined value, and fading pitch estimating means for estimating a fading pitch based on the obtained time And a fading pitch estimation apparatus comprising: 2. A comparison means for comparing each difference calculated by the difference calculation means with a predetermined threshold value and sending only a difference equal to or more than the predetermined threshold value to the integration means. 1. The fading pitch estimation device according to 1. 3. The difference calculating means compares two reception levels continuously sampled by the sampling means with a predetermined level, and if both of the two reception levels are equal to or higher than the predetermined level. The fading pitch estimating apparatus according to claim 1, wherein a difference between the two reception levels is calculated. 4. The difference calculating means calculates the difference between the two reception levels if at least one of the two reception levels continuously sampled by the sampling means has a reception level equal to or higher than a predetermined level. The fading pitch estimating apparatus according to claim 1, wherein the fading pitch estimating apparatus calculates the fading pitch. 5. An average reception level detection means for detecting an average reception level of the reception levels is further provided, and the fading pitch estimation means is detected by the time calculated by the time measurement means and the average reception level detection means. The fading pitch estimating apparatus according to claim 1, wherein the fading pitch is estimated based on the average received level. 6. A fading pitch estimation apparatus in a mobile communication system, a timing signal generating means for generating a plurality of types of timing signals having different cycles, and a sampling means for sampling a reception level of a reception signal based on the plurality of types of timing signals. A difference calculating means for calculating the difference between the sampled reception levels for each type of the timing signal; an integrating means for integrating each of the calculated differences for each type of the timing signal; And a fading pitch estimating means for estimating a fading pitch based on each of the obtained times, the time until the obtained value exceeds a predetermined value for each type of the timing signal. Fading pitch estimation device. 7. The fading pitch estimating means selects any one of the times obtained by the time measuring means according to the magnitude of each of the times, and relates to the type of timing signal to which the selected time belongs. 7. The fading pitch estimating apparatus according to claim 6, wherein the selected time is converted into a fading pitch by referring to a conversion table. 8. A fading pitch estimation device in a mobile communication system, comprising: a sampling means for sampling a reception level of a reception signal at a predetermined cycle;
If the reception level of at least one of the two reception levels is equal to or higher than a predetermined level, a difference calculation means for calculating a difference between the two reception levels, and each calculated difference is compared with a predetermined threshold, A comparison unit that outputs a drive signal when the drive signal is equal to or more than a predetermined threshold, a count unit that receives the drive signal and counts up each time the drive signal is input, and a count value obtained by the count unit exceeds a predetermined value. And a fading pitch estimating means for estimating a fading pitch on the basis of the obtained time, and a fading pitch estimating device. 9. The difference calculating means compares two reception levels continuously sampled by the sampling means with a predetermined level, and if both of the two reception levels are equal to or higher than the predetermined level. The fading pitch estimating apparatus according to claim 8, wherein a difference between the two reception levels is calculated. 10. An average reception level detection means for detecting an average reception level of the reception levels is further provided, and the fading pitch estimation means is detected by the time calculated by the clock means and the average reception level detection means. 9. The fading pitch estimating apparatus according to claim 8, wherein the fading pitch is estimated based on the average received level. 11. A fading pitch estimation device in a mobile communication system, a timing signal generating means for generating a plurality of types of timing signals having different cycles, and a sampling means for sampling a reception level of a reception signal based on the plurality of types of timing signals. A difference calculating means for calculating a difference between each of the sampled reception levels for each type of the timing signal; and comparing each calculated difference with a predetermined threshold for each type of the timing signal, the predetermined threshold A comparing unit that outputs a drive signal at the above time, a count unit that receives the drive signal and counts up for each input of the drive signal according to the type of the timing signal, and a count value obtained by the count unit is predetermined. Calculate the time to exceed the value for each type of timing signal And a fading pitch estimating means for estimating a fading pitch on the basis of each of the obtained times, and a fading pitch estimating device. 12. The fading pitch estimating means comprises:
Any one of the respective times obtained by the time measuring means is selected according to the magnitude of each of these times, and the selected time is referred to by referring to the conversion table regarding the type of the timing signal to which the selected time belongs. 12. The fading pitch estimation device according to claim 11, wherein the fading pitch is converted into a fading pitch.