JP4577074B2 - Selective receiving method and receiving apparatus - Google Patents

Description

  The present invention relates to a selective reception method and a receiving apparatus, and more particularly to a selective reception method in which a transmission signal from one signal source is received by a plurality of reception means and a reception signal having the highest quality is selected from the plurality of reception signals. And a receiving apparatus.

  In a receiving device used for monitoring received voices, etc., a transmission signal (target wave) from one signal source (radio wave transmission source) is received by a plurality of receivers with different installation locations, and the most of the received signals. Select a received signal with good quality. Since the received signal is an audio signal, the operator who is the receiver determines the received audio signal with the highest quality by listening.

  That is, even with the same target wave, the S / N (signal-to-noise ratio) of the received signal is different if the installation location of the receiver is different. When the radio wave source is a moving body, the S / N varies according to the change in the distance between the radio wave source and the receiver. In addition, since the receiver is located at a short distance from the radio wave transmission source, even if the S / N is relatively high, the S / N is temporarily deteriorated due to the influence of the obstacle, and there is a prospect that it is far from the radio wave transmission source. The S / N may be better for the receiver installed at the position. Therefore, it is necessary for the operator to select the received sound signal having the best S / N by listening to the received sound signal of the target wave obtained by receiving with the plurality of receivers having different installation locations.

  As a receiving device similar to the above-described conventional receiving device, a sonar receiving device that searches for the position of an underwater object moving at high speed has been conventionally known (for example, see Patent Document 1). In the conventional receiving device described in Patent Document 1, the outputs of a plurality of receiving circuits are recorded in a recording circuit, and a reception signal in the vicinity specified by the signal at the time of transmission in the recording circuit and the cursor range signal is cut out. By constructing a structure that outputs to the listening circuit while repeating the process of continuous joining in time, it enables the operator to use visual and auditory at the same time to search for underwater objects efficiently. Can do.

  Also, the signal from the signal source is received by multiple receiver elements, the received signals from the multiple receiver elements are subjected to beam forming, the received signals are correlated, and the peak position is detected. A passive ranging device that estimates a signal arrival time difference from a signal source and estimates the position of the signal source from the estimation result and the position of the receiver element is also known (see, for example, Patent Document 2).

JP-A-1-233384 JP-A-8-082666

  However, the conventional method of selecting the received audio signal having the best S / N by listening to the received audio signal of the target wave of one signal source obtained by receiving by a plurality of receivers with different installation locations. In the receiving apparatus, in order for the operator to select a reception voice signal with the best S / N, it is necessary to listen to other reception voice signals with a bad S / N for comparison, and only the voice signal with the best S / N is received. It is impossible to listen continuously. Therefore, an unnecessary procedure is required until the best received S / N received audio signal is selected. As a result, there is a problem that the real-time property is lacking.

  In addition, the conventional receiving device described in Patent Document 1 is a configuration in which the changeover switch is configured to switch an audio signal by an operator's manual selection operation, and requires an operator's operation. Like the conventional device described above, Again, the best S / N received audio signal cannot be heard in real time.

  Furthermore, the passive ranging device which is a conventional receiving device described in Patent Document 2 includes a plurality of receiver elements each including a plurality of receiver elements, and a beam forming process is performed on the received signals from the plurality of receiver elements. Depending on the part, processing for beam forming so as to have the maximum sensitivity in the signal direction is necessary, and there is a problem that the configuration is complicated and expensive. In addition, an SN estimation processing unit that calculates an SN ratio by calculating a variance value and a correlation value of the arrival time difference is provided, and this is a preset ratio of the calculated variance value and correlation value and an SN ratio. Thus, there is a problem in the reliability of the obtained SN ratio.

  The present invention has been made in view of the above points, and with a simple configuration, among the received audio signals obtained by receiving the target waves from one signal source with a plurality of receivers, the S / N ratio is the highest. It is an object of the present invention to provide a selective reception method and a reception apparatus that can automatically select a good reception audio signal.

To achieve the above object, the first invention is a selection reception method most S / N in a plurality of information signals received to select a good information signal, a transmission signal from one signal source n The first step of receiving separately by n (n is a natural number of 3 or more) receivers, and n distributors provided on a one-to-one basis corresponding to the n receivers, The second step of distributing the information signal received by 2 in two and the total of n (n-1) of different combinations among the n information signals distributed in two in the second step. / A third step of calculating a multiplication value between two information signals and a square value of each of n information signals, and n (n−1) obtained by the third step ) / 2 pieces of multiplication values and n square values, The correlation coefficient that is the ratio of the cross-correlation between two information signals of different combinations of the information signals and the product of the autocorrelation of the two information signals is all between the two information signals of different combinations. The S / N of one of the n information signals is calculated from the fourth step of calculating and the correlation coefficient calculated in the fourth step, and the S / N of one of the n information signals is calculated. A fifth step of obtaining a selection signal indicating one of the information signals having the highest S / N, and the highest S / N among the n distributors based on the selection signal obtained by the fifth step. And a sixth step of selecting and outputting the other information signal divided into two from one distributor that outputs one of the N information signals .

  In this invention, the S / N of each information signal (for example, audio signal) obtained by receiving by each of a plurality of receivers is calculated, and only the information signal having the best S / N is selected. Output.

In order to achieve the above object, according to a second aspect of the present invention, there is provided a selective reception method for selecting an information signal having the best S / N among a plurality of received information signals, and a transmission signal from one signal source. Are separately received by n receivers (n is a natural number of 3 or more) and each of n distributors provided in a one-to-one correspondence with n receivers, A second step of distributing the information signal obtained by receiving by the receiver into two and a total of n (n−n−) in different combinations among the n information signals divided into two in the second step. 1) / 2 A third step of calculating a multiplication value between two information signals and a square value of each of n information signals, and n (n) obtained by the third step -1) / 2 multiplication values and n square values, The correlation coefficient, which is the ratio of the cross-correlation between two information signals of different combinations of the information signals and the product of each autocorrelation of the two information signals, between the two information signals of different combinations The S / N of one of the n information signals is calculated from the fourth step in which all the calculations are performed and the correlation coefficient calculated in the fourth step, and the S / N of each of the n information signals is calculated. A fifth step of obtaining a selection signal indicating one information signal having the highest S / N among N, and the highest S of n distributors based on the selection signal obtained by the fifth step A sixth step of selecting and outputting the other information signal distributed in two from one distributor outputting one information signal of / N, and one of the n pieces of information calculated in the fifth step The seventh step for displaying the S / N of the signal Characterized in that it comprises a flop. According to the present invention, it is possible to simultaneously output and display an information signal having the best S / N.

In order to achieve the above object, the receiving device of the third invention includes n receivers (n is a natural number of 3 or more) for separately receiving transmission signals from one signal source, and n receivers . It is provided on a one-to-one basis corresponding to the receiver, and distributes the information signal obtained by receiving by the receiver into two, totaling n distributors and n distributors in two A total of n (n-1) / 2 information signals, and the square of each of the n information signals. Each of the n information signals by using multiplication means for calculating each value, n (n-1) / 2 multiplication values obtained by the multiplication means, and n square values. Cross-correlation between two information signals each having a different combination, and each of the two information signals. A calculation means for calculating and calculating all correlation coefficients, which are ratios to the product of self-correlation, between the two information signals in different combinations, and the n number of the correlation coefficients calculated by the calculation means. Comparison means for calculating S / N of one information signal and obtaining a selection signal indicating the one information signal having the highest S / N among the S / Ns of the n information signals Based on the selection signal obtained by the means, of the n distributors, the other information signal distributed in two from one distributor outputting one information signal having the highest S / N is obtained. And selecting means for selecting and outputting . In this invention, the S / N of each information signal (for example, audio signal) obtained by receiving by n receivers is calculated, and only the information signal with the best S / N is selected among them. Can be output.

In order to achieve the above object, the fourth invention provides n receivers (n is a natural number of 3 or more) for separately receiving transmission signals from one signal source, and n receivers. Correspondingly, it is provided in a one-to-one correspondence, and the information signal obtained by receiving by the receiver is divided into two, n distributors in total, and n each divided into two by n distributors A total of n (n-1) / 2 information signals in different combinations among the one information signal and a square value of each of the n information signals. Each of the one information signal among the n information signals is calculated using multiplication means for calculating, n (n-1) / 2 multiplication values obtained by the multiplication means, and n square values. The product of the cross-correlation between two information signals of different combinations and the respective autocorrelations of the two information signals Calculating means for calculating all the correlation coefficients between the two information signals in different combinations, and the n information signals from the correlation coefficients calculated by the calculating means. S / N of each of the n information signals and a comparison signal for obtaining a selection signal indicating the one information signal having the highest S / N among the S / Ns of the one information signal. Based on the selection signal, among the n distributors, the other information signal distributed in two from one distributor that outputs one information signal having the highest S / N is selected and output. And a display means for displaying the S / N of one of the n information signals calculated by the comparison means .

  According to the present invention, a transmission signal from one signal source is received by a plurality of receiving means, and the S / N of each received signal is calculated by correlating the received signal from the received signal, Since the reception signal with the best S / N is selected, the operator can always continuously select and output the reception information signal with the best S / N without performing a selection operation.

  Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a block diagram of an embodiment of a receiving apparatus according to the present invention. In the figure, the receiving apparatus of the present embodiment includes three receivers 2-1 to 2-3 for receiving transmission signals from one signal source 1 independently of each other, and these three receivers. Audio signal selection unit 3 for automatically selecting the audio signal having the best S / N from the received audio signals received and demodulated at 2-1 to 2-3, and the audio output unit for outputting the audio 4.

  The audio signal selection unit 3 is provided in a one-to-one correspondence with the receivers 2-1, 2-2, 2-3, and distributes the input audio signals into two distributors 31, 32 and 33. A comparator 34 that outputs a selection signal for selecting a voice signal having the best S / N by comparing the level of the voice signals output from the units 31 to 33, and a voice signal output from the distributors 31 to 33 The selection switch 35 selects one audio signal corresponding to the selection signal and outputs it to the audio output unit 4.

  FIG. 2 shows a block diagram of one embodiment of the comparator 34 described above. As shown in the figure, the comparator 34 has a first phase relationship based on the output signals of the multipliers 340 to 345 that respectively multiply and output the input audio signals and the multipliers 340, 341, and 342. A computing unit 346 that computes and outputs the number correl (1,2), and a computing unit 347 that computes and outputs the second correlation coefficient correl (3,1) based on the output signals of the multipliers 340, 345, and 344; , A computing unit 348 that computes and outputs the third correlation coefficient correl (2,3) based on the output signals of the multipliers 342, 343, and 344, and the output signals of the computing units 346, 347, and 348. And an arithmetic unit 349 for generating and outputting a selection signal for selecting the audio signal having the best S / N from among the S / N.

  Next, the operation of FIGS. 1 and 2 will be described. The transmission signals transmitted from the signal source 1 in FIG. 1 are received independently from each other by the three receivers 2-1, 2-2, and 2-3 installed at different positions. The receivers 2-1, 2-2, and 2-3 demodulate the received signal and output audio signals # 1, # 2, and # 3, respectively. The distributor 31 distributes the input audio signal # 1 into two, one is input to the first input terminal of the selection switch 35 and the other is supplied to the comparator 34. Similarly, the distributor 32 distributes the input audio signal # 2 into two, one is input to the second input terminal of the selection switch 35 and the other is supplied to the comparator 34, and the distributor 33 is input. The audio signal # 3 is divided into two and one is input to the third input terminal of the selection switch 35 and the other is supplied to the comparator 34.

  Here, the audio signals # 1, # 2, and # 3 are represented by the sum of the signal components S1, S2, and S3 and the noise components N1, N2, and N3, respectively. That is, the level of the audio signal # 1 is represented by (S1 + N1) which is the sum of the signal component S1 and the noise component N1. Similarly, the level of the audio signal # 2 is represented by the sum of the signal component S2 and the noise component N2 (S2 + N2), and the level of the audio signal # 3 is the sum of the signal component S3 and the noise component N3. It is expressed by (S3 + N3).

  In general, the correlation coefficient between two quantitative variables X and Y: correl (X, Y) is calculated from variance: var (X), var (Y), and covariance: covar (X, Y). The definition formula is as follows.

correl (X, Y)
= Covar (X, Y) / (√var (X) · √var (Y)) (1)
Therefore, the correlation coefficient between the audio signal # 1 and the audio signal # 2 is correl (1, 2), the covariance is covar (1, 2), the variance of the audio signal # 1 is var (1), and the audio signal # 2 The correlation coefficient correl (1, 2) is expressed by the following equation where var is a variance of var (2).

correl (1,2)
= Covar (1,2) / (√var (1) · √var (2)) (2)
Here, covar (1, 2) is the cross-correlation between audio signal # 1 and audio signal # 2, var (1) is the autocorrelation of audio signal # 1, and var (2) is the autocorrelation of audio signal # 2. . Since the signal component, the noise component, and the different noise components are not correlated, the multiplication value can be ignored, so the following approximate expression is established.

covar (1,2) = S1 · S2 (3)
var (1) = S1 ² + N1 ² (4)
var (2) = S2 ² + N2 ² (5)
From the above, 1 / {correl (1,2)} ² is obtained and factored to obtain the following expression.

1 / {correl (1,2)} ²
= {1+ (N1 ² / S1 ² )} · {1+ (N2 ² / S2 ² )} (6)
Similarly, if the correlation coefficient between the audio signal # 2 and the audio signal # 3 is correl (2, 3) and the correlation coefficient between the audio signal # 3 and the audio signal # 1 is correl (3, 1), Get.

1 / {correl (2,3)} ²
= {1+ (N2 ² / S2 ² )} · {1+ (N3 ² / S3 ² )} (7)
1 / {correl (3,1)} ²
= {1+ (N3 ² / S3 ² )} · {1+ (N1 ² / S1 ² )} (8)
Therefore, the arithmetic unit 346 in the comparator 34 is a square output (S1 + N1) ^{2 of} the audio signal # 1 output from the multiplier 340 and a multiplication output of the audio signals # 1 and # 2 output from the multiplier 341. Based on {(S1 + N1) · (S2 + N2)} and the square output (S2 + N2) ^{2 of} the audio signal # 2 output from the multiplier 342, a phase that is a 1/2 power of the reciprocal of equation (6) The relation number correl (1, 2) is calculated and output.

Similarly, the calculator 347 outputs the square output (S1 + N1) ^{2 of} the audio signal # 1 output from the multiplier 340 and the multiplication output {(S1 + N1) of the audio signals # 1 and # 3 output from the multiplier 345. Based on (S3 + N3)} and the square output (S3 + N3) ^{2 of} the audio signal # 3 output from the multiplier 344, the correlation coefficient correl ( 3 and 1), and the calculator 348 outputs the square output (S2 + N2) ^{2 of} the audio signal # 2 output from the multiplier 342 and the audio signals # 2 and # output from the multiplier 343. 3 multiplication output {(S2 + N2) · (S3 + N3)} and the square output (S3 + N3) ^{2 of} the audio signal # 3 output from the multiplier 344, to the 1/2 power of the reciprocal of equation (7) Correlation coefficient correl (2, 3) as output Is computed and output.

Here, when 1 / {correl (1,2)} ² , 1 / {correl (2,3)} ² and 1 / {correl (3,1)} ² are A, B, and C, respectively, (6 Equations (8) to (8) are represented by the following equations.

A = {1+ (N1 ² / S1 ² )} · {1+ (N2 ² / S2 ² )} (9)
B = {1+ (N2 ² / S2 ² )} · {1+ (N3 ² / S3 ² )} (10)
C = {1+ (N3 ² / S3 ² )} · {1+ (N1 ² / S1 ² )} (11)
From the formulas (9) to (11), each S / N is represented by the following formula.

S1 / N1 = √ (1 / (| √ (A · C / B) −1) |) (12)
S2 / N2 = √ (1 / (| √ (A · B / C) −1) |) (13)
S3 / N3 = √ (1 / (| √ (B · C / A) −1) |) (14)
Therefore, the calculator 349 in the comparator 34 shown in FIG. 2 performs calculations of the formulas (12) to (14) based on the correlation coefficient outputs of the calculators 346 to 348 to obtain the calculation. A highest value is selected from among S1 / N1, S2 / N2, and S3 / N3, a selection signal for selecting a voice signal indicating the selected S / N is generated, and is sent to the selection switch 35 in FIG.

  In this way, the audio signal with the best S / N among the audio signals # 1, # 2 and # 3 is automatically selected by the selection switch 35 and supplied to the audio output unit 4, thereby being subjected to electro-acoustic conversion. Thus, the sound with the best S / N is generated and listened to by the operator. Thus, according to the present embodiment, the operator can always continuously listen to the sound with the best S / N without performing the selection operation as in the prior art. Thus, the operator can accurately monitor the contents and characteristics of the voice information transmitted from the signal source 1 during operation without using a test signal or the like. Further, according to the present embodiment, rather than estimating the S / N of the received audio signal using a preset correspondence table or the like, the S / N itself of each of the plurality of received audio signals is compared, Since an audio signal with the best S / N is selected from among them, a more reliable audio signal can be selected.

  In FIG. 1, the transmission signal from one signal source 1 is received by the three receivers 2-1 to 2-3, and the S / N is the best among the three demodulated audio signals # 1 to # 3. In this embodiment, an audio signal is selected. However, as shown in FIG. 3, the receiver may be provided in N units (where N is a natural number of 4 or more). In this case, in the audio signal selection unit 5, distributors 51-1 to 51-N provided in a one-to-one correspondence with the receivers 2-1 to 2-N and distributors 51-1 to 51-51. The -N audio signals # 1 to #N are configured by a comparator 52 that generates a selection signal for selecting the audio signal having the best S / N with the same configuration as in FIG. .

  Next, another embodiment of the present invention will be described. FIG. 4 shows a block diagram of another embodiment of a receiving apparatus according to the present invention. In the figure, the same components as those in FIG. In FIG. 4, the audio signal selector 6 includes distributors 61, 62, 63 provided in a one-to-one correspondence with the three receivers 2-1, 2-2, 2-3, And a selection switch 64 that selects one of the audio signals output from the audio signals 62 and 63 and outputs the selected audio signal to the audio output unit 4.

  Further, the S / N calculator 7 has a configuration substantially the same as that of the comparator 34 out of all three audio signals # 1 to # 3 output from the distributors 61, 62, and 63. In addition to outputting S / N information indicating the S / N of each audio signal represented by the equation (14), a selection signal is also output. The S / N display 8 displays the S / N of each audio signal calculated by the S / N calculator 7.

  In this embodiment, the S / N of each audio signal calculated by the S / N calculator 7 is displayed on the S / N display 8 and the S / N calculator 7 has the best S / N. A selection signal for selecting an audio signal is supplied to the selection switch 64, and the audio signal having the best S / N is selected by the selection switch 64 and output to the audio output unit 4. In this embodiment, the operator does not perform a selection operation as in the prior art, and continuously listens to the sound with the best S / N, and sends the S / N of each sound signal to the S / N display 8. Can be visually recognized.

  The present invention is not limited to the above embodiment. For example, in the embodiment of FIG. 4, N receivers may be provided as in FIG. In the above embodiments, the receiver is described as demodulating the received signal and outputting an audio signal. However, the receiver receives an information signal other than the audio signal (for example, a video signal). May be.

It is a block diagram of one embodiment of the present invention. It is a block diagram of one Embodiment of the comparator in FIG. It is a block diagram which shows the modification of FIG. It is a block diagram of other embodiments of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Signal source 2-1 to 2-N receiver 3 Audio | voice signal selection part 4 Audio | voice output part 7 S / N calculator 8 S / N display 31-33, 51-1 to 51-N, 61-63 Divider 34, 52 Comparator 35, 53, 64 Select switch 340-345 Multiplier 346-349 Calculator

Claims (4)

In a selective reception method for selecting an information signal having the best S / N among a plurality of received information signals,
A first step of separately receiving transmission signals from one signal source by n (n is a natural number of 3 or more) receivers;
A second step of distributing the information signal received by the receiver into two by each of n distributors provided on a one-to-one basis corresponding to the n receivers;
A total of n (n-1) / 2 information signals multiplied by two different combinations among the one information signal divided into two in the second step, and the n information signals. A third step of calculating each square value of one of the information signals,
Using the n (n−1) / 2 multiplication values and the n square values obtained in the third step, 2 different combinations of the n information signals of the one of the n information signals. A fourth step of calculating and calculating a correlation coefficient that is a ratio of a cross-correlation between the two information signals and a product of each autocorrelation of the two information signals for each of the two information signals in different combinations; ,
The S / N of each of the n information signals is calculated from the correlation coefficient calculated in the fourth step, and the S / N of the n one information signals is the highest. A fifth step of obtaining a selection signal indicating the one information signal of S / N;
Based on the selection signal obtained in the fifth step, among the n distributors, the other distributed from one distributor that outputs one of the highest S / N information signals. And a sixth step of selecting and outputting the information signal . In a selective reception method for selecting an information signal having the best S / N among a plurality of received information signals,
A first step of separately receiving transmission signals from one signal source by n (n is a natural number of 3 or more) receivers;
A second step of distributing the information signal received by the receiver into two by each of n distributors provided on a one-to-one basis corresponding to the n receivers;
A total of n (n-1) / 2 information signals multiplied by two different combinations among the one information signal divided into two in the second step, and the n information signals. A third step of calculating each square value of one of the information signals,
Using the n (n−1) / 2 multiplication values and the n square values obtained in the third step, 2 different combinations of the n information signals of the one of the n information signals. A fourth step of calculating and calculating a correlation coefficient that is a ratio of a cross-correlation between the two information signals and a product of each autocorrelation of the two information signals for each of the two information signals in different combinations; ,
The S / N of each of the n information signals is calculated from the correlation coefficient calculated in the fourth step, and the S / N of the n one information signals is the highest. A fifth step of obtaining a selection signal indicating the one information signal of S / N;
Based on the selection signal obtained in the fifth step, among the n distributors, the other distributed from one distributor that outputs one of the highest S / N information signals. A sixth step of selecting and outputting the information signal;
Seventh step and wherein the to that selection reception method to include the displaying of the S / N of the fifth said n of said one information signal calculated in step. N receivers (n is a natural number of 3 or more) for separately receiving transmission signals from one signal source;
A total of n distributors that are provided in a one-to-one correspondence with the n receivers and that distribute the information signal obtained by receiving by the receiver into two;
A total of n (n−1) / 2 information signals multiplied by two different combinations of the one information signal divided into two by the n distributors, and n Multiplication means for calculating a square value of each of the one information signal,
Using the n (n−1) / 2 multiplication values and n square values obtained by the multiplication means, two pieces of information in different combinations from among the n information signals. A calculation means for calculating and calculating all correlation coefficients between the two information signals in different combinations, each of which is a ratio of a cross-correlation between the signals and a product of each autocorrelation of the two information signals;
The S / N of the n information signals is calculated from the correlation coefficient calculated by the calculating means, and the highest S / N among the S / Ns of the n information signals is calculated. Comparing means for obtaining a selection signal indicating the one information signal of N;
Based on the selection signal obtained by the comparison means, the other information distributed in two from one distributor that outputs one information signal of the highest S / N among the n distributors. And a selection unit that selects and outputs a signal . N receivers (n is a natural number of 3 or more) for separately receiving transmission signals from one signal source;
A total of n distributors that are provided in a one-to-one correspondence with the n receivers and that distribute the information signal obtained by receiving by the receiver into two;
A total of n (n−1) / 2 information signals multiplied by two different combinations of the one information signal divided into two by the n distributors, and n Multiplication means for calculating a square value of each of the one information signal,
Using the n (n−1) / 2 multiplication values and n square values obtained by the multiplication means, two pieces of information in different combinations from among the n information signals. A calculation means for calculating and calculating all correlation coefficients between the two information signals in different combinations, each of which is a ratio of a cross-correlation between the signals and a product of each autocorrelation of the two information signals;
The S / N of the n information signals is calculated from the correlation coefficient calculated by the calculating means, and the highest S / N among the S / Ns of the n information signals is calculated. Comparing means for obtaining a selection signal indicating the one information signal of N;
Based on the selection signal obtained by the comparison means, the other information distributed in two from one distributor that outputs one information signal of the highest S / N among the n distributors. A selection means for selecting and outputting a signal;
And a display unit for displaying S / N of the n information signals calculated by the comparison unit .

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