JPH09326739A - Diversity receiver and receiver provided with error correction function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a reception signal with deteriorated transmission quality from being selected. SOLUTION: Reception signals R1, R2 received from the air via antennas 1, 2 are given respectively to receivers 3, 4 from which reception data D1, D2 are reproduced. Furthermore, normal level detection circuits 11, 12 detect a normal level from a reception electric field strength of the reception signals R1, R2 detected by the receivers 3, 4. Level comparators 13, 14 compare the reception electric field strength of the reception signals R1, R2 with the normal level to detect the fluctuation in the reception electric field strength. A level comparator 15 compares the normal level of the reception electric field strength of the reception signals R1, R2 and informs a reception signal whose level is higher to a diversity control circuit 16. The diversity control circuit 16 controls a selection output circuit 5 to provide an output of received data of the reception signal with less fluctuation from the normal level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile radio communication device, a diversity receiver used for its radio base station device, and a receiver having an error correction function.

[0002]

2. Description of the Related Art As is well known, it is known that a communication method using a diversity technique in wireless communication is an effective method for efficient communication. FIG. 10 shows the configuration of a conventional diversity receiver.

The received signal received by the receiver 3 from the space via the antenna 1 and the received signal received by the receiver 4 via the antenna 2 are input to the level comparator 50 and the control unit 60. . Then, the received electric field strengths of the two received signals are compared by the level comparator 50, and the comparison result is notified to the control unit 60. Then, the control unit 60 selectively outputs the received signal having the higher received electric field strength to the signal processing unit (not shown) in the subsequent stage.

However, when transmission distortion occurs due to a delayed wave or the like, higher reception electric field strength does not always mean better transmission quality. For example, the reception signal received by the antenna 1 has an average reception level of -30 dBm,
The reception signal received by the antenna 2 has an average reception level of -5.
It is assumed that it is 0 dBm. However, it is assumed that the level of the received signal received by the antenna 1 is lowered to -40 dBm due to the change of the code of a specific bit due to the influence of the delayed wave, and the received signal received by the antenna 2 is as follows. It is assumed that no failure has occurred.

Even in such a case, in the above-mentioned conventional diversity receiver, the reception signal received by the antenna 2 is received by the antenna 1 having a high average reception level, although the reception quality is better. Therefore, the received signal is selectively output.

Further, in a particularly large-scale communication system, when the radio zones of the base stations are overlapped or close to each other due to restrictions on the frequency used, the radio waves transmitted from the mobile communication terminal PS2 are transmitted as shown in FIG. Not only the base station BS2, which is the communication partner, but also the base station BS1, which is not the communication partner, arrives as an interference wave. Therefore, the base station BS1 which is not the communication partner may not selectively output the radio wave from the mobile communication terminal PS1 which is the original communication partner.

Conventionally, the above problems have been dealt with by performing error correction on received data, but this method also causes erroneous selection due to interference waves between radio zones of the base stations BS1 and BS2. Is inevitable.

There is also a method of using an equalizer that is effective for the delayed wave, but if there is an interference wave, it is impossible to remove the influence of the interference wave, which may deteriorate the transmission quality.

[0009]

In the conventional receiving apparatus,
Since the data transmission route is selected according to the magnitude of the received electric field strength, a data transmission route with a lot of transmission distortion affected by interference waves and delayed waves from other wireless zones may be selected. However, there was a problem that the signal of another wireless zone was selected.

The present invention has been made to solve the above problems, and provides a diversity receiver capable of preventing selection of a reception signal having poor transmission quality even if the reception electric field strength is high. The purpose is to

Another object of the present invention is to provide a diversity receiving apparatus capable of preventing the reception signal having poor transmission quality from being selected even when the same signal is received with a delay. To do.

Further, according to the present invention, even if the received electric field strength of the received signal addressed to the own station is smaller than that of the received signal addressed to the other station, for example, due to the influence of the interference wave or the delayed wave from the other radio zone, It is an object of the present invention to provide a diversity receiver capable of selectively outputting a reception signal addressed to a station.

A further object of the present invention is to provide a diversity receiver capable of performing error correction by using these received signals when a plurality of the same signals are received. A further object of the present invention is to provide a diversity receiver capable of correcting an error generated in received data due to level fluctuation.

[0014]

In order to achieve the above object, a diversity receiver according to the present invention is a diversity receiver for selecting an optimum received signal among a plurality of received signals obtained by a plurality of receiving systems. In the device, a received electric field strength detecting means for detecting electric field strengths of a plurality of received signals, and a level fluctuation of the received electric field strength due to a change in transmission data of each received signal detected by the received electric field strength detecting means are detected. The level fluctuation detecting means and the signal selecting means for preferentially outputting the received signal whose level fluctuation is equal to or lower than a predetermined level based on the detection result of the level fluctuation detecting means.

The diversity receiving apparatus having the above-mentioned configuration focuses on the possibility that an error may occur in the received data when the level variation of the electric field strength due to the change in the transmitted data of the received signal is large, and a plurality of received signals are received. Among the signals, the received signal whose level fluctuation of the received electric field strength is below a predetermined level is preferentially selected and output.

Therefore, according to the diversity receiver having the above structure, it is possible to prevent the reception signal having the poor transmission quality from being selected even if the reception electric field strength is high.
Further, the diversity receiving apparatus according to the present invention receives the same transmission signal by a plurality of receiving systems, and selects the optimum receiving signal from the plurality of receiving systems. A plurality of received electric field strength detecting means for respectively detecting electric field strength; a level fluctuation detecting means for detecting a level fluctuation of the received electric field strength due to a change in transmission data of each received signal detected by the received electric field strength detecting means; Based on the synchronization information detecting means for detecting the synchronization information from the reception data of the reception signal and the synchronization information detected by the synchronization information detecting means, the level fluctuation for the same reception data is compared, and the reception signal with the small level fluctuation is detected. A signal selecting means for preferentially selecting and outputting is provided.

In the diversity receiver having the above configuration, when a plurality of the same signals are received, the level fluctuations corresponding to the same data are compared from the synchronization information of these received signals, and the transmission data of the plurality of received signals are compared. The received signal whose level fluctuation of the received electric field strength due to the change is below a predetermined level is preferentially selected and output.

Therefore, according to the diversity receiving apparatus having the above configuration, it is possible to prevent the reception signal having poor transmission quality from being selected even when the same signal is received with a delay.

Further, the diversity receiving apparatus according to the present invention is a diversity receiving apparatus for selecting an optimum receiving signal from a plurality of receiving signals obtained by a plurality of receiving systems. It comprises an address information detecting means for detecting, and a signal selecting means for selectively outputting a received signal addressed to the receiver among a plurality of received signals based on the address information detected by the address information detecting means. I did it.

In the diversity receiver having the above structure, the address information is detected, the received signal addressed to the own station is determined, and the received signal addressed to the own station is selectively output. Therefore, according to the diversity receiving apparatus having the above configuration, even when the received electric field strength of the received signal addressed to the own station is smaller than that of the received signal addressed to the other station, the received signal addressed to the own station can be selectively output.

Further, the diversity receiving apparatus according to the present invention is a diversity receiving apparatus which selects an optimum receiving signal from a plurality of receiving signals obtained by a plurality of receiving systems, and compares a plurality of receiving data by comparing received data. Correlation detection means for obtaining the correlation between signals, grouping means for grouping received signals that are regarded as the same from the detection result of the correlation detection means among a plurality of received signals, and the same group by this grouping means The received data of the received signals divided into groups are compared with each other, and error correction means for performing error correction by correcting different data is provided.

In the diversity receiver having the above structure, the same received signal is detected by correlating the data of a plurality of received signals, the data of the same received signal are compared, and different data are corrected. I am trying to correct errors.

Therefore, according to the diversity receiver having the above configuration, when a plurality of the same signals are received, error correction can be performed using these received signals.
In order to achieve the above object, a receiving device having a function of performing an error correction process according to the present invention includes a receiving electric field strength detecting means for detecting electric field strength of a received signal and a receiving electric field strength detecting means for detecting the electric field strength. Based on the detection result of the level fluctuation detecting means and the level fluctuation detecting means for detecting the level fluctuation associated with the change in the transmission data of the received electric field strength, the level fluctuation of the level fluctuation is detected. Data correction means for correcting the received data of the generated received signal is provided and configured.

The receiving device having the function of performing the error correction processing having the above-mentioned configuration focuses on the possibility that an error will occur in the received data when the level fluctuation of the electric field strength of the received signal is large. The received data having a level change above the level is corrected. Therefore, according to the receiving device having the function of performing the error correction process, it is possible to correct the error generated in the received data due to the level variation.

[0025]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. A diversity receiver according to the first embodiment of the present invention will be described. FIG. 1 shows the configuration. However, in FIG. 1, the same parts as those in FIG. 10 showing the configuration of the conventional diversity receiver are denoted by the same reference numerals.

The reception signal R1 received from the space through the antenna 1 is input to the receiver 3 and reproduced as reception data D1. Similarly, the reception signal R2 received from the space via the antenna 2 is input to the receiver 4 and reproduced as reception data D2. These received data D1 and D2
Are input to the selection output circuit 5, respectively.

Further, the receiver 3 is provided with, for example, a reception electric field strength detection unit (RSSI), detects the reception electric field strength of the reception signal R1, and inputs the detection result to the normal level detection circuit 11 and the level comparator 13. . Similarly, the receiver 4 is also provided with, for example, a reception electric field strength detection unit (RSSI), detects the reception electric field strength of the reception signal R2, and inputs the detection result to the normal level detection circuit 12 and the level comparator 14.

The normal level detection circuit 11 receives the received signal R1.
The normal level of the received electric field strength is detected, and the detection result is input to the level comparator 13 and the level comparator 15.
Similarly, the normal level detection circuit 12 detects the normal level of the reception electric field strength of the reception signal R2 and inputs the detection result to the level comparator 14 and the level comparator 15.

The normal level is the average of the received electric field strengths detected in the vicinity of the center of each data (sample 1 in FIG. 2) as shown in FIG. 2 for a plurality of data.

The level comparator 13 compares the received electric field strength of the received signal R1 with the normal level detected by the normal level detection circuit 11 to detect a variation in the received electric field strength of the received signal R1. Then, the detection result is input to the diversity control circuit 16.

Similarly, the level comparator 14 receives the received signal R
The received electric field strength of No. 2 is compared with the normal level detected by the normal level detection circuit 12, the variation of the received electric field strength of the received signal R2 is detected, and the detection result is input to the diversity control circuit 16.

The level comparator 15 compares the normal level of the received electric field strength of the received signal R1 with the normal level of the received electric field strength of the received signal R2, and sends the received signal of the higher normal level to the diversity control circuit 16. Notice.

The diversity control circuit 16 receives the received data of the received signal of which the received electric field strength is equal to or higher than the preset reference level and has less fluctuation from the normal level,
The selective output circuit 5 is controlled to selectively output to a data processing unit (not shown) in the subsequent stage. FIG. 3 shows an example of the control flow.

First, the diversity control circuit 16 selects and outputs the reception data of the reception signal of the higher normal level in response to the notification of the comparison result from the level comparator 15 at the initial stage of operation. 5 is controlled (step 8a). Then, it is monitored whether or not the variation of the received electric field strength of the received signal being selectively output exceeds a predetermined value (step 8b).

If the predetermined value is exceeded, the process proceeds to step 8c, and it is determined whether the normal level of the other (non-selected) received signal is equal to or higher than the reference level. Here, if it is equal to or higher than the reference level, step 8d
To step 8b, otherwise to step 8b.

In step 8d, it is determined whether or not the variation of the other received signal is within the predetermined value. Here, if it is within the predetermined value, the process proceeds to step 8e, and the selection output circuit 5 is controlled so as to selectively output the reception data of the other reception signal. On the other hand, if not, the process proceeds to step 8b.

That is, in the diversity receiver having the above-mentioned configuration, the one having the received electric field strength equal to or higher than the reference level and less varying from the normal level based on the received electric field strength of the two received signals and the variation from the normal level. The reception data of the reception signal is selectively output.

Therefore, according to the diversity receiving apparatus having the above-mentioned configuration, a received signal having a large fluctuation from the normal level is not selected even if the received electric field strength is high, and therefore a received signal having poor transmission quality is selected. Can be prevented.

Next, a diversity receiver according to the second embodiment of the present invention will be described. FIG. 4 shows the configuration. However, in FIG. 4, the same parts as those in FIG. 1 showing the configuration of the diversity receiving apparatus of the first embodiment are denoted by the same reference numerals, and different parts will be mainly described here.

The reception signal R1 received from the space through the antenna 1 is input to the receiver 3 and reproduced as reception data D1. The received data D1 is sent to the data buffer circuit 2 of the sync detection circuit 21 and the buffer circuit 23.
31 is input. Similarly, the reception signal R2 received from the space via the antenna 2 is input to the receiver 4 and reproduced as reception data D2. And this received data D2
Is input to the data buffer circuit 241 of the synchronization detection circuit 22 and the buffer circuit 24.

The received signal R detected by the receiver 3
The received electric field strength of 1 is input to the normal level detection circuit 11 and the level comparator 13. Similarly, the received electric field strength of the received signal R2 detected by the receiver 4 is input to the normal level detection circuit 12 and the level comparator 14.

The normal level detection circuit 11 receives the received signal R1.
The normal level of the received electric field strength is detected, and the detection result is input to the level comparator 13 and the level comparator 15.
Similarly, the normal level detection circuit 12 detects the normal level of the reception electric field strength of the reception signal R2 and inputs the detection result to the level comparator 14 and the level comparator 15.

The level comparator 13 compares the received electric field strength of the received signal R1 with the normal level detected by the normal level detection circuit 11 to detect a variation in the received electric field strength of the received signal R1. Then, this detection result is input to the reception status buffer circuit 232 of the buffer circuit 23.

Similarly, the level comparator 14 receives the received signal R
2 is compared with the normal level detected by the normal level detection circuit 12 to detect a variation in the received electric field strength of the reception signal R2, and the detection result is detected by the buffer circuit 2
4 into the reception status buffer circuit 242.

The level comparator 15 compares the normal level of the received electric field strength of the received signal R1 with the normal level of the received electric field strength of the received signal R2, and sends the received signal of the higher normal level to the diversity control circuit 25. Notice.

The sync detection circuit 21 detects sync information from the received data D1 and inputs this sync information to the buffer circuit 23. Similarly, the synchronization detection circuit 22 receives the received data D
2, the synchronization information is detected, and this synchronization information is input to the buffer circuit 24.

The buffer circuit 23 comprises a data buffer circuit 231 for buffering the reception data D1 and a reception status buffer circuit 232 for buffering the data corresponding to the fluctuation of the reception electric field strength, and corresponds to the above synchronization information. Then, the received data D1 and the data showing the variation of the received electric field strength at the time of receiving the data D1 are recorded.

Then, the reception data D1 buffered by the data buffer circuit 231 is input to the selection output circuit 5, and the data of the fluctuation of the reception electric field strength buffered by the reception status buffer circuit 232 is transmitted together with the synchronization information. It is input to the control circuit 25.

Like the buffer circuit 23, the buffer circuit 24 comprises a data buffer circuit 241 for buffering the received data D2 and a reception status buffer circuit 242 for buffering the data corresponding to the fluctuation of the received electric field strength. , Receive data D2 is processed in the same manner as buffer circuit 23.

Then, the reception data D2 buffered by the data buffer circuit 241 is input to the selection output circuit 5, and the data of the fluctuation of the reception electric field strength buffered by the reception status buffer circuit 242 together with the synchronization information is diversity. It is input to the control circuit 25.

The diversity control circuit 25 monitors the variation data of the reception electric field strength of the same data of the reception data D1 and the reception data D2 based on the synchronization information. Then, the reception data of the reception signal whose reception electric field strength is equal to or higher than the reference level and whose variation from the normal level is small is selectively controlled by the selective output circuit 5 to be selectively output to the subsequent data processing unit (not shown). It is what is output.

That is, in the diversity receiving apparatus having the above-mentioned configuration, the variation of the received electric field strength of the two received signals from the normal level is detected, and the synchronization information is detected from the received data of each received signal. Then, based on this synchronization information, the fluctuations for the same reception data are compared, and the reception data whose reception electric field strength is equal to or higher than the reference level and whose fluctuation from the normal level is small are selectively output. ing.

Therefore, according to the diversity receiver having the above configuration, even when the two receivers 3 and 4 receive the same signal with a delay, transmission is performed based on the variation corresponding to the same received data. It is possible to select the received signal of higher quality.

Next, a diversity receiver according to the third embodiment of the present invention will be described. FIG. 5 shows the configuration. However, in FIG. 5, the same parts as those in FIG. 1 showing the configuration of the diversity receiving apparatus of the first embodiment are designated by the same reference numerals, and different parts will be mainly described here.

The reception signal R1 received from the space through the antenna 1 is input to the receiver 3 and reproduced as reception data D1. Similarly, the reception signal R2 received from the space via the antenna 2 is input to the receiver 4 and reproduced as reception data D2. These received data D1 and D2
Are input to the buffer circuit 31 and the buffer circuit 32, respectively.

The received signal R detected by the receiver 3
The received electric field strength of 1 and the received electric field strength of the received signal R2 detected by the receiver 4 are respectively the level comparator 37.
Is input to

Buffer circuit 31 and buffer circuit 32
Buffers the received data D1 and D2 that are respectively input, and the corresponding error correction circuits 33 and
It is input to the error correction circuit 34.

Then, the received data D1 is subjected to error correction processing by the error correction circuit 33, and then input to the address detection circuit 35 and the selection output circuit 5. Similarly, the received data D2 is subjected to error correction processing by the error correction circuit 34 and then input to the address detection circuit 36 and the selection output circuit 5.

The address detection circuit 35 and the address detection circuit 36 detect the destination address included in the received data respectively input, and input the detection result to the diversity control circuit 38.

On the other hand, the level comparator 37 receives the received electric field strengths of the received signal R1 and the received signal R2, respectively, compares the two received electric field strengths, and notifies the diversity control circuit 38 of the higher received signal. To do.

The diversity control circuit 38 determines from the detection result of the destination address whether or not the received signal is addressed to its own station, and controls the selective output circuit 5 to selectively receive the received signal addressed to its own station. The data is output to a data processing unit (not shown) in the subsequent stage. Further, when both the received signal R1 and the received signal R2 are received signals addressed to the own station, based on the detection result of the level comparator 37, the received signal with the higher received electric field strength is output. To control the selective output circuit 5.

That is, in the diversity receiver having the above-mentioned configuration, after performing error correction processing on each of the two received signals, the destination address is detected, the received signal addressed to the own station is determined, and the selective reception is selectively performed. The received signal addressed to the station is output to the data processing unit (not shown) in the subsequent stage. Further, when both of the two received signals are received signals addressed to the own station, the received signal with the higher received electric field strength is output.

Therefore, according to the diversity receiver having the above configuration, even when the received electric field strength of the received signal addressed to the own station is smaller than that of the received signal addressed to the other station, the received signal addressed to the own station is selectively output. be able to. Also, if both of the two received signals are received signals addressed to the own station, the received signal with the higher received electric field strength can be output.

The present invention is not limited to the above embodiment. For example, in the above configuration, the address detection circuit 35 and the address detection circuit 36 are used to detect the address of the reception destination from the reception signal and determine the reception signal addressed to the own station. The address may be detected and selected and output based on the detection result.

Further, in the above-mentioned first to third embodiments, the diversity receiving apparatus having the receivers of two systems has been described as an example. However, the present invention is not limited to this, and can be applied to a diversity receiver having receivers of three or more systems. Next, the fourth aspect of the present invention
The diversity receiving apparatus according to the embodiment will be described. FIG. 6 shows the configuration. However, FIG.
In FIG. 5, the same parts as those in FIG. 5 showing the configuration of the diversity receiver of the third exemplary embodiment are designated by the same reference numerals.

Antennas 41a, 41b, 41c from the space
And a received signal Ra received via 41d,
Rb, Rc and Rd are input to the receivers 42a, 42b, 42c and 42d corresponding to the above antennas and reproduced as reception data Da, Db, Dc and Dd.

Then, these received data Da to Dd
Are corresponding buffer circuits 43a, 43b, 4
3c and 43d, and after being buffered by each buffer circuit, they are input to the correlation detection circuit 44 and the grouping circuit 46.

The correlation detection circuit 44 receives the received data Da to D.
The correlation between each data of d is detected, and the detection result is input to the group determination circuit 45. As a method of detecting the correlation here, for example, the data from the buffer circuits 43a to 43d are compared with each other bit by bit, the number of different data is counted, and the count result is used as the correlation result.

The group determination circuit 45 is the correlation detection circuit 4
Based on the correlation result detected in 4, the received data D
The same data among a to Dd is judged and the judgment result is inputted to the grouping circuit 46.

For example, when the number of received data in one frame is 255, the correlation result (the number of different data) detected by the correlation detection circuit 44 is Da-Db.
The distance is "120", the distance between Da and Dc is "6", the distance between Da and Dd is "122", the distance between Db and Dc is "124", and Db-Dd.
It is assumed that the distance is “8” and the distance between Dc and Dd is “125”.

In such a case, since the error rates between Da and Dc and between Db and Dd are low, the received signals Ra and R are
c is determined to be the same signal, and the received signals Rb and R
It is determined that d and the same signal.

The grouping circuit 46 determines the same signal among the received data Da to Dd as the same error correction circuit 47 on the basis of the judgment result of the group judgment circuit 45.
(Or the error correction circuit 48).

For example, as described above, the received data Da and D
When it is determined that c is the same as the received data Db and Dd, the received data Da and Dc are input to the error correction circuit 47 and the received data Db and Dd are input.
d is input to the error correction circuit 48.

The error correction circuit 47 is a grouping circuit 4
The received data input from 6 are compared to detect different data in bit units. Then, after correcting the different data, error detection is performed. If there is an error, a new correction is added to the detected different data to detect the error. If you repeat this operation and the error no longer exists,
The corrected received data is input to the address detection circuit 35 and the selection output circuit 5.

The error correction circuit 48 also performs error correction in the same manner as the error correction circuit 47, and when the error does not exist in the end, the corrected received data is input to the address detection circuit 36 and the selection output circuit 5. .

The address detection circuit 35 and the address detection circuit 36 detect the destination address contained in the input combined reception signals, and input the detection result to the diversity control circuit 49.

The diversity control circuit 49 judges from the detection result of the destination address whether or not the received signal is addressed to its own station, and controls the selective output circuit 5 to selectively receive the received signal addressed to its own station. The data is output to a data processing unit (not shown) in the subsequent stage.

That is, in the diversity receiver having the above configuration, the same received signal is detected among the four received signals by comparing the data included in the four received signals, and the received signals are grouped. Then, signals in the same group are compared with each other to detect different data, and the data is corrected. Then, the destination address included in the combined received signal is detected to determine whether or not the received signal is addressed to the own station, and the received signal addressed to the own station is selectively output to a data processing unit (not shown) in the subsequent stage. ).

Therefore, according to the diversity receiving apparatus having the above configuration, it is possible to perform error correction using a plurality of the same received data and reproduce the error-free received data. Further, even when the received electric field strength of the received signal addressed to the own station is smaller than that of the received signal addressed to the other station, the received signal addressed to the own station can be selectively output.

In the above configuration, the address detection circuit 3
5 and the address detection circuit 36 are used to detect the destination address from the received signal to determine the received signal addressed to the own station. However, the source address is detected from the received signal and the detection result is detected. You may make it selectively output based on.

Next, a receiver having an error correction function according to the fifth embodiment of the present invention will be described. FIG. 7 shows the configuration. However, in FIG. 7, the same parts as those in FIG. 1 showing the configuration of the diversity receiving apparatus according to the first embodiment are designated by the same reference numerals.

The received signal R10 received by the receiver 30 from the space via the antenna 1 is the clock extraction circuit 5
1, the sample and hold circuit 53a, the sample and hold circuit 53b, and the sign determination circuit 56.

The clock extraction circuit 51 receives the received signal R10.
The clocks included in are extracted, and the extraction results are input to the clock generation circuit 52a and the clock generation circuit 52b. Clock generation circuit 52a and clock generation circuit 5
2b is for generating a sampling clock based on the clock extracted by the clock extraction circuit 51. As shown in FIG. 2, the clock generation circuit 52a generates a clock (hereinafter, referred to as a first sampling clock) at a timing (sample 1 in FIG. 2) for sampling the vicinity of the central portion of each data, This clock is input to the sample hold circuit 53a.

Further, the clock generation circuit 52b generates a clock (hereinafter referred to as a second sampling clock) at the timing (sample 2 in FIG. 2) for sampling between data, and this clock is sent to the sample hold circuit 53b. input.

The sample and hold circuit 53a has the first
Using the sampling clock of, the received electric field strength level near the data center of the received signal R10 is read and sampled and held. Here, the read reception electric field strength level is input to the level averaging circuit 54.

The level averaging circuit 54 obtains a normal reception level by averaging the reception electric field strength levels input from the sample hold circuit 53a for a predetermined number of samples. Then, the obtained normal level is input to the level comparator 55.

On the other hand, the sample hold circuit 53b uses the second sampling clock to receive the received signal R1.
The received electric field strength level between the data of 0 is read and sample-held, and the read received electric field strength level is input to the level comparator 55.

The level comparator 55 receives the electric field strength level (normal level) near the center of the averaged data.
And the received electric field strength level between the data are compared, and the comparison result is input to the data correction circuit 57 as data correctness information.

The sign judging circuit 56 judges the sign of the received signal R10, reproduces the received data D10, and inputs it to the data correction circuit 57. The data correction circuit 57 identifies an error portion existing in the received data D10 from the data correctness information and corrects the data at that portion. The data D10 'corrected here is input to the error detection circuit 58.

The error detection circuit 58 includes a data correction circuit 57.
It is to detect whether or not there is an error in the reception data D10 'corrected in. The error detection here is performed by, for example, CRC (Cyclic Redundancy Check). If the received data D10 'has no error, the received data from the data correction circuit 57 is output as it is. On the other hand, if there is an error in the received data,
This data is again input to the data correction circuit 57, and a new correction is added to the above-mentioned correction location.

That is, as shown in FIG. 2, the receiving apparatus having the error correction function of the above-mentioned configuration has a difference between the received electric field strength level (normal level) near the center of the data and the received electric field strength level between the data. Focusing on the possibility that an error will occur in the received data when it is large, the received electric field strength of the received data is monitored to detect the part where the level fluctuated, and the received data at that part is corrected. I am trying to apply.

Therefore, according to the receiving apparatus having the error correction function of the above configuration, it is possible to correct the error in the received data due to the decrease in the reception level and the random noise generated from the receiver due to this decrease in the level. it can.

Next explained is a receiving apparatus having an error correction function according to the sixth embodiment of the invention. FIG. 8 shows the configuration. However, in FIG. 8, the same parts as those in FIG. 7 showing the configuration of the diversity receiver of the fifth exemplary embodiment are denoted by the same reference numerals.

The reception signal R10 received by the receiver 30 from the space via the antenna 1 is the clock extraction circuit 5
1, input to the sign determination circuit 56 and the change amount measurement circuit 62. The clock extraction circuit 51 uses the received signal R10.
The clock included in is extracted, and the extraction result is input to the level variation window generation circuit 61.

The level fluctuation window generation circuit 61 counts the clocks from the clock extraction circuit 51 using, for example, a counter, and generates a window that opens and closes at a timing according to the count number. The window thus generated is input to the change amount measuring circuit 62.
The window created here is created so as to open between received data as shown in FIG.

The change amount measuring circuit 62 measures the change amount of the level of the received signal R10 (shown by the one-dot chain line in FIG. 9) while the window is open by differentiating. The measurement result is input to the high frequency detection circuit 63.

The high frequency detecting circuit 63 is a variation measuring circuit 62.
Among the amount of change in the level of the received signal R10 obtained in step 1, a change of a predetermined level or more is detected, and the detection result is input to the data correction circuit 57 as data error information.

The sign judging circuit 56 judges the sign of the received signal R10, reproduces the received data D10, and inputs it to the data correction circuit 57. The data correction circuit 57 identifies an error location existing in the received data D10 from the data error information and corrects the data at the location. The data D10 'corrected here is input to the error detection circuit 58.

The error detection circuit 58 includes a data correction circuit 57.
It is to detect whether or not there is an error in the reception data D10 'corrected in. The error detection here is performed by, for example, CRC (Cyclic Redundancy Check). If the received data D10 'has no error, the received data from the data correction circuit 57 is output as it is. On the other hand, if there is an error in the received data,
This data is again input to the data correction circuit 57, and a new correction is added to the above-mentioned correction location.

That is, the receiving apparatus having the above-described error correction function generates an error in the received data when the drop (level change amount) in the received electric field strength level between the data surrounded by the one-dot chain line in FIG. 9 is large. When the received electric field strength between the above-mentioned data is below a predetermined level, the received data at that portion is corrected.

Therefore, according to the receiving apparatus having the error correction function of the above configuration, it is possible to correct the error in the received data due to the decrease in the reception level and the random noise generated from the receiver due to this decrease in the level. it can. It goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0102]

As described above, in the diversity receiving apparatus according to the present invention, the level fluctuation detecting means and the signal selecting means are newly provided so that the level fluctuation of the received electric field strength among a plurality of received signals has a predetermined level. The following received signals are preferentially selected and output. Therefore, according to the present invention, it is possible to provide a diversity receiving apparatus capable of preventing a reception signal having poor transmission quality from being selected even if the reception electric field strength is high.

Further, in the present invention, level fluctuation detecting means, synchronization information detecting means, and signal selecting means are newly provided, and when a plurality of the same signals are received, the same synchronization information is obtained from these reception signals. The level fluctuations corresponding to the data are compared with each other, and among the plurality of received signals, the received signal whose level fluctuation of the received electric field strength is equal to or lower than a predetermined level is preferentially selected and output. Therefore, according to the present invention, it is possible to provide a diversity receiving apparatus capable of preventing a reception signal having poor transmission quality from being selected even when the same signal is received with a delay.

Further, in the present invention, the address information detecting means and the signal selecting means are newly provided, the address information is detected to judge the received signal addressed to the own station, and the received signal addressed to the own station is selectively selected. I am trying to output. Therefore, according to the present invention, even if the received electric field strength of the received signal addressed to the own station is smaller than that of the received signal addressed to the other station, the diversity receiving apparatus capable of selectively outputting the received signal addressed to the own station. Can be provided.

Further, according to the present invention, the correlation detecting means,
A grouping unit and an error correction unit are newly provided, the same received signal is detected by correlating the data of a plurality of received signals, the data of the same received signal are compared, and different data are corrected. By adding it, error correction is performed. Therefore, according to the present invention, when a plurality of the same signals are received, it is possible to provide a diversity receiving apparatus capable of performing error correction using these received signals.

Further, in the present invention, the level fluctuation detecting means and the data correcting means are newly provided to correct the received data having the level fluctuation of a predetermined level or more. Therefore, according to the present invention, it is possible to provide a receiving device having a function of performing error correction capable of correcting an error that occurs in received data due to level fluctuation.

[Brief description of drawings]

FIG. 1 is a circuit block diagram showing a configuration of a diversity receiving device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the relationship between the electric field strength of the reception signal and the reception data of the diversity receiver shown in FIG.

FIG. 3 is a flowchart for explaining control of a diversity control circuit of the diversity receiving device shown in FIG.

FIG. 4 is a circuit block diagram showing a configuration of a diversity receiving apparatus according to a second embodiment of the present invention.

FIG. 5 is a circuit block diagram showing a configuration of a diversity receiving device according to a third embodiment of the present invention.

FIG. 6 is a circuit block diagram showing a configuration of a diversity receiving device according to a fourth embodiment of the present invention.

FIG. 7 is a circuit block diagram showing a configuration of a receiving apparatus having an error correction function according to a fifth embodiment of the present invention.

FIG. 8 is a circuit block diagram showing a configuration of a receiving device having an error correction function according to a sixth embodiment of the present invention.

9 is a diagram for explaining the relationship between the electric field strength of the reception signal and the reception data of the reception device having the error correction function shown in FIG.

FIG. 10 is a circuit block diagram showing a configuration of a conventional diversity receiver.

FIG. 11 is a diagram for explaining an interference wave caused by overlapping of wireless zones of base stations.

[Explanation of symbols]

1, 2, 41a to 41d ... Antenna 3, 4, 30, 42a to 42d ... Receiver 5 ... Selection output circuit 11, 12 ... Normal level detection circuit 13, 14, 15, 37, 55 ... Level comparator 16, 25 , 38, 49 ... Diversity control circuit 21, 22 ... Synchronization detection circuit 23, 24, 31, 32, 43a to 43d ... Buffer circuit 231, 241 ... Data buffer circuit 232, 242 ... Reception status buffer circuit 33, 34 ... Error correction Circuits 35, 36 ... Address detection circuit 44 ... Correlation detection circuit 45 ... Group determination circuit 46 ... Grouping circuit 47, 48 ... Error correction circuit 51 ... Clock extraction circuit 52a, 52b ... Clock generation circuit 53a, 53b ... Sample hold circuit 54 ... Level averaging circuit 56 ... Sign determination circuit 57 ... Data correction circuit 58 ... Error detection Circuit 60 ... Control unit 61 ... Level fluctuation window generation circuit 62 ... Change amount measurement circuit 63 ... High frequency detection circuit

Claims (5)

[Claims] 1. A diversity receiving apparatus for selecting an optimum received signal from a plurality of received signals obtained by a plurality of receiving systems, a received electric field strength detecting means for respectively detecting electric field strengths of the plurality of received signals, Level fluctuation detecting means for detecting a level fluctuation of the received electric field strength due to a change in transmission data of each reception signal detected by the received electric field strength detecting means, and the level fluctuation based on the detection result of the level fluctuation detecting means. And a signal selecting means for preferentially outputting a received signal of a predetermined level or less. 2. A diversity receiver that receives the same transmission signal by a plurality of reception systems and selects an optimum reception signal from the plurality of reception systems, and detects the electric field strengths of the plurality of reception signals obtained by the plurality of reception systems, respectively. A received electric field strength detecting means, a level fluctuation detecting means for detecting a level fluctuation of the received electric field strength caused by a change in transmission data of each received signal detected by the received electric field strength detecting means, Based on the synchronization information detecting means for detecting the synchronization information respectively from the received data, and the synchronization information detected by the synchronization information detecting means,
A diversity receiving apparatus comprising: a signal selecting unit that compares the level fluctuations with respect to the same received data and preferentially outputs a received signal with a small level fluctuation. 3. A diversity receiver for selecting an optimum received signal among a plurality of received signals obtained by a plurality of receiving systems, address information detecting means for detecting address information included in the plurality of received signals, A diversity receiving apparatus comprising: a signal selecting means for selectively outputting a received signal addressed to the receiver among the plurality of received signals based on the address information detected by the address information detecting means. 4. A diversity receiver for selecting an optimum received signal from a plurality of received signals obtained by a plurality of receiving systems, correlation detection for obtaining correlation between the plurality of received signals by comparing received data. Means, grouping means for grouping received signals that are regarded as the same from the detection result of the correlation detection means among the plurality of received signals, and received signals grouped into the same group by this grouping means A diversity receiving apparatus comprising: an error correcting unit for performing error correction by comparing the received data of 1. and correcting the different data. 5. A receiving device having a function of performing error detection processing on a received signal, the receiving electric field strength detecting means detecting the electric field strength of the received signal, and the receiving electric field strength detecting means detecting the electric field strength. Based on the detection result of the level fluctuation detecting means, the level fluctuation detecting means for detecting the level fluctuation associated with the change in the transmission data of the received electric field strength, and if the level fluctuation is equal to or higher than a predetermined level, A receiving apparatus having an error correction function, comprising: a data correcting unit that corrects received data of the generated received signal.