Signal receiving method and signal receiving device

Abstract

To adjust, in diversity reception for receiving a plurality of signals, delays of the signals with a simple configuration to maintain the continuity of signals regardless of characteristics unique to the signals.SOLUTION: A signal receiving method includes: transmitting two or more diversity-received received signals in separate transmission systems; converting the frequency of the received signals transmitted in the transmission systems into an intermediate frequency; controlling the amplitude of the signals after the conversion of the frequency to a predetermined amplitude; converting the signals to digital signals; converting the digital signals to baseband signals; selecting and delaying either one of one baseband signal and the other baseband signal; performing phase adjustment by adjusting the phases of the delayed baseband signal and the non-delayed baseband signal to a reference signal (standard signal); combining the amplitudes of the phase-adjusted one baseband signal and the other baseband signal; detecting the phase difference between the baseband signals whose amplitudes are combined; performing phase adjustment based on the detected phase difference; and selecting, from the two or more baseband signals whose amplitudes and phases are adjusted, the baseband signal transmitted through one of the transmission systems and outputting the selected baseband signal.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a diversity receiving method and a signal receiving device for receiving a plurality of wireless or wired signals transmitted from a communication station, a broadcasting station, an artificial satellite, or the like. [Background technology]

[0002] Radio waves can experience a phenomenon known as fading, where multiple radio waves interfere with each other due to reflection from obstacles or as they travel various paths, causing changes in the strength and other characteristics of the radio waves. Fading can disrupt stable reception at receiving stations, making it difficult to watch and listen to video and audio. Therefore, in order to improve radio wave conditions caused by fading, receiving stations in wireless broadcasting and communication systems and cable television (CATV) systems, for example, use a diversity reception method, which receives signals using two or more antennas and combines or selects one of the signals to maintain a stable signal. In a diversity reception method, the multiple antennas are spaced apart, have different heights and orientations (receiving directions), and are polarized to receive two or more radio waves in different states, thereby achieving greater stability.

[0003] CATV systems are constructed to provide diversity reception of signals received by the antenna of a local station and signals transmitted from other stations. Electrical signals are typically converted into optical signals and transmitted over optical fiber between the local station and other stations, but in recent years, signals are also transmitted over IP (Internet Protocol) communication.

[0004] In a diversity reception system that receives multiple signals, the received signals pass through different paths, resulting in differences in delay, phase, amplitude, etc. If diversity is performed when differences exist, the continuity of the signals is lost, and image reproduction on the receiver may be temporarily interrupted. To ensure continuity, the delay, phase, and amplitude of the multiple signals must be matched. Matching the delay is particularly important in systems where one receiving point is far from another, as delay differences become larger. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-199683 [Patent Document 2] Japanese Patent Application Publication No. 9-284188 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-109492

[0006] Fig. 6 is a block diagram showing the configuration of a conventional diversity receiving system. Fig. 6 shows a receiving device that adjusts the phases of OFDM signals diversity received by a plurality of antennas 1000 and performs combining or selection by combining / selecting device 1030. Examples of such receiving devices include Patent Documents 1 to 3.

[0007] In the case of a method of combining signals in the receiving device of Fig. 6 (combining method), multiple signals received by multiple antennas 1000 are converted to an intermediate frequency compatible with an analog / digital converter in receiving section 1010, and then further converted to a digital IF signal in analog / digital converter 1020. Then, the signals are phase-aligned in combining / selecting device 1030, and combined according to the level of the received signal to improve the quality of the received signal before being output (used).

[0008] 6, in the case of the selection method by the receiving device, similarly to the combining method, multiple signals received by multiple antennas 1000 are converted to an intermediate frequency by receiving unit 1010, and then further converted to a digital IF signal by analog / digital converter 1020. After that, the signal phases are aligned in combining / selecting device 1030, and the signal with the highest reception level is selected and output (used).

[0009] The receiving devices of Patent Documents 1 to 3 use a guard interval (GI) specific to OFDM signals to match the delays of multiple received signals, which causes a problem that they cannot be applied to signals of different modulation methods that do not have characteristics such as GI. Furthermore, for delay amounts that exceed the delay adjustable range specific to the modulation method, there are methods that demodulate the signal up to the final stage and use a synchronization pattern or the like included in the original data, or methods that use FFT, but these methods result in a complex configuration of the receiving device, which causes a problem of increasing the manufacturing cost of the receiving device.

[0010] Furthermore, in the method of synchronizing multiple signals using synchronization patterns contained in the demodulated original data, if one of the multiple signals becomes out of sync, all signals will be simultaneously degraded, resulting in problems such as block noise and blackouts that can shock the receiver. Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to solve the above problems and to provide a configuration that can be implemented at low cost, regardless of the modulation method or transmission method of multiple signals received using diversity, and that can match delays and maintain signal continuity and quality. [Means for solving the problem]

[0012] (Signal reception method) The signal receiving method of the present invention is a signal receiving method that can combine the delays of two or more signals received by a diversity receiving system, and is a signal receiving method using a selection system and a signal receiving method using a synthesis system.

[0013] (Signal reception method: Selectable) Among the signal receiving methods of the present invention, the selective signal receiving method transmits two or more received signals received by a diversity system via separate transmission systems, and converts the frequencies of the received signals transmitted via each transmission system to an intermediate frequency. The amplitude (level) of each frequency-converted received signal is controlled to a predetermined level, each received signal is converted into a digital signal, and each digital signal is converted into a baseband signal. One of the baseband signals and the other baseband signal is selected and delayed, and the phases of the delayed baseband signal and the non-delayed baseband signal are adjusted to match a reference signal (reference signal). The signal receiving method matches the amplitudes (amplitude amounts) of one of the phase-adjusted baseband signals and the other baseband signal, detects a phase difference between the amplitude-matched baseband signals, matches the phases of the baseband signals based on the detected phase difference, selects one transmission system from the two or more baseband signals whose amplitudes and phases have been matched, and outputs the baseband signal of the selected transmission system.

[0014] (Signal reception method: synthesis method) Among the signal receiving methods of the present invention, the signal receiving method of the combining method is the same as the selection method up to the detection of the phase difference, except that after the phase difference detection, the quality of the baseband signals transmitted through each of two or more transmission systems is measured, and based on the measurement results, the baseband signals are combined and output so as to achieve the best signal quality.

[0015] In the signal reception method of the present invention, in any of the signal reception methods described above, the time (delay value) for delaying the baseband signal can be switched and changed, the baseband signal after the difference value detection is averaged, the delay value is controlled while waiting for the time until the average value becomes constant, the delay value is switched and changed to the delay value when the averaged value becomes the smallest, and the signal can be delayed by the delay value after the switching and change.

[0016] (signal receiving device) The signal receiving device of the present invention is a signal receiving device that can match the delays of two or more signals received by a diversity system, and is a signal receiving device of a selection system and a signal receiving device of a synthesis system.

[0017] (Signal receiving device: selective type) In the present invention, a selective signal receiving device includes two or more transmission systems for separately transmitting two or more received signals. The signal receiving device includes a frequency converter for converting the frequency of the received signals transmitted through each transmission system to an intermediate frequency, a first automatic gain control device for controlling each of the frequency-converted received signals to a predetermined level, an analog-to-digital converter for converting each of the level-controlled received signals to a digital signal, and a quadrature demodulator for converting the digital signal to a baseband signal. The signal receiving device further includes a delay device for delaying the baseband signal after quadrature demodulation to reduce the delay difference between the signals of the two or more transmission systems, a switching device for switching between signals to be input to the delay device and signals not to be input, a reference signal generator for generating a reference signal for phase adjustment, and a delay control device for controlling the two or more transmission systems. is transmitted The system further comprises a phase adjustment device that adjusts the phase of a baseband signal to the reference signal, a second automatic gain control device that adjusts the amplitude of one baseband signal phase-adjusted by the phase adjustment device and the other baseband signal, a phase detection device that detects the phase difference between one baseband signal amplitude-adjusted by the second automatic gain control device and the other baseband signal, a phase adjustment device that adjusts the phase of the baseband signals based on the detected phase difference, and a combining / selecting device that selects one transmission system from the baseband signals amplitude-adjusted by the second automatic gain control device and outputs the baseband signal of the selected transmission system.

[0018] (Signal receiving device: synthesis method) In the present invention, the signal receiving device of the synthesis system is phase The process up to the detection device is the same as in the selection method. The difference is that a signal quality measurement device is provided for each of the two or more transmission systems to measure the quality of the baseband signal, and the output from the signal quality measurement device is input to the combining / selecting device, so that the combining / selecting device can combine two or more signals to achieve the best signal quality based on the measurement results from the signal quality measurement device.

[0019] The signal receiving device of the present invention is phase The baseband signal after the difference value detection is output to the output side of the detector. The difference value of Averaging device that averages and difference The value becomes constant (Stabilize) to of time (sampling time for averaging) a delay device control device that controls the delay value of the delay device while waiting; difference A differential minimum storage value storage device stores the stored value of the delay device when the value becomes minimum, the transmission system at that time, and switches the delay values ​​of the delay device control device and the differential minimum delay value storage device. memory Device memory It may also be equipped with a value switching device. [Effects of the Invention]

[0020] The signal receiving method and signal receiving device of the present invention have the following advantages. (1) The delay between signals of multiple transmission systems, which could previously only be adjusted within a fixed range such as the GI period, can now be adjusted without using complex circuits such as OFDM demodulation circuits. (2) Since no signal modulation method is used, it is not dependent on the modulation method. Signal The delay and phase can be adjusted, and it can be used for diversity reception of any signal. (3) The delay amount of the signal transmitted through two or more transmission systems can be converted into the difference in amplitude to adjust the delay adjustment device, so that delay adjustment can be performed at low cost and in a short time. (4) Since the signal quality can be measured inside the signal receiving device, the signal can be processed taking into account the tendency of signal degradation before the signal deteriorates and affects the received image, thereby maintaining signal continuity and preventing accidents in which the image becomes invisible. (5) The phase of the signal is adjusted to match the reference signal, so that signals transmitted through two or more transmission systems do not affect each other, maintaining signal continuity and preventing accidents that cause the image to become invisible. (6) By connecting the transmission systems in cascade or in parallel, it is possible to accommodate three or more transmission systems, enabling diversity reception of multiple signals. (7) The delay value can be switched and changed, improving the accuracy of delay adjustment. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a block diagram showing the configuration of a first embodiment of the present invention. [Figure 2] FIG. 10 is a block diagram showing the configuration of a second embodiment of the present invention. [Figure 3] FIG. 10 is a block diagram showing the configuration of a third embodiment of the present invention. [Figure 4] FIG. 10 is a block diagram showing the configuration of a fourth embodiment of the present invention. [Figure 5] 4 is a flowchart showing the operation of FIG. 3, which is a modification of FIG. 1; [Figure 6] FIG. 1 is a block diagram showing the configuration of a conventional diversity receiving system. DETAILED DESCRIPTION OF THE INVENTION

[0022] The following describes embodiments of a signal receiving method and a signal receiving device according to the present invention. The following embodiments are merely examples of the present invention. The present invention is not limited to these embodiments, and other configurations and functions may be used as long as they can solve the problems of the invention.

[0023] (Signal Receiving Method Embodiment 1: When Using the Signal Receiving Device of FIG. 1) The signal receiving method of the present invention will be described below using the signal receiving device of Figure 1 as an example for diversity reception. The following description is for a case where there are two input terminals, but the present invention may have any number of input terminals greater than or equal to two.

[0024] 1, a signal S1 is input to input 1 from an antenna or repeater (not shown), and a signal S2 is input to input 2. Although input signal S1 and input signal S2 are the same signal, the routes they take to reach the respective input terminals are different (propagation conditions in the case of radio waves, differences in transmission path length (route difference) in the case of repeater signals, conditions such as relative dielectric constant), and therefore there are differences in signal conditions such as delay, phase, amplitude, and signal quality.

[0025] The received input signals S1 and S2 are transmitted through separate transmission lines L1 and L2, and are converted to an intermediate frequency compatible with the Nyquist zone of the analog-to-digital converter 14 by the frequency converters 11 of the respective transmission lines L1 and L2.

[0026] The level of the frequency-converted signal is automatically controlled by a first automatic gain control device 12, which incorporates a signal level that matches the dynamic range of an analog-to-digital converter (ADC) 14 as a reference, to ensure that the signal level is the same as the reference. This reference is set by the user, and the user can select and determine a level that is lower than the dynamic range of the analog-to-digital converter 14 and as unaffected by noise as possible. The purpose of adjusting the level here is to prevent degradation of the signal-to-noise ratio due to excessive or insufficient input, since the dynamic range of the analog-to-digital converter 14 is limited. Therefore, this level adjustment is to keep the input level within the dynamic range of the analog-to-digital converter 14.

[0027] The signal level controlled as described above is passed through a band elimination filter (e.g., a SAW filter) 13 to remove unwanted signals outside the Nyquist zone, extracting a signal of the desired frequency, which is then converted into a digital signal by an analog-to-digital converter 14.

[0028] The digital signal is separated (demodulated) into an In-Phase signal (I signal) and a Quadrature-Phase signal (Q signal) (collectively referred to as "IQ signal") by an orthogonal demodulator 15, and information on the amplitude and phase of the signal can be obtained.

[0029] There is a delay difference between input signal S1 and input signal S2 due to the difference in transmission route. In order to eliminate or reduce this delay difference, the digital signal that arrives earlier is input to delay adjustment device (delay device) 17 and output after being delayed by the time of the delay difference, while the digital signal that arrives later is output as is. The delay adjustment device 17 can select which signals to input to the delay adjustment device (delay device) 17 and which signals not to input.

[0030] The delay adjustment device 17 can store delay times (hereinafter referred to as "delay values") at sampling time intervals. For example, when a signal is converted into a digital signal at a sampling frequency of 10 MHz, the sampling time is the reciprocal of the sampling frequency, which is 100 nanoseconds. In this case, if the delay value of the delay adjustment device 17 is set to 1 and stored, the signal will be delayed by 100 nanoseconds. By storing an arbitrary delay value, the signal can be delayed by the time calculated by multiplying the sampling time by the stored delay value. The delay value can be set to a delay time calculated from, for example, the route difference between the input signal S1 and the input signal S2, the relative dielectric constant, the electrical length of the transmission path, etc.

[0031] Among the signals quadrature-demodulated by the quadrature demodulator 15, the delayed signal of the transmission system is input to the delay adjustment device 17, and the non-delayed signal is not input to the delay adjustment device 17, thereby making it possible to make the delay amounts of both transmission systems the same at the sampling interval. The operation of the delay adjustment device 17 will be described. If the delay adjustment device 17 has, for example, an address numbered 1000, and the bit storage capacity per address is 32 bits, and if, for example, one digital signal sampled at 10 MHz in the analog-to-digital converter 14 is quadrature-demodulated by the quadrature demodulator 15 and the IQ signals are each 16 bits, the IQ signals can be stored at each address by using the most significant 16 bits of one address as the I signal and the least significant 16 bits as the Q signal. The delayed signal of the transmission system is not input to the delay adjustment device 17, and is therefore output at a relative address of 0. When a non-delayed transmission signal arrives at the delay adjustment device 17 first, if the non-delayed signal is held and not output until the delay adjustment device 17 reaches address 1000, it will be output simultaneously with the delayed transmission signal at relative address 0. Since the non-delayed transmission signal is output with a delay of 1000 samples, it can be output with a time delay of 100 usec. If the output address is set to 500, it can also be configured to be output with a time delay of 50 usec.

[0032] The digital signals are input to a phase adjustment device 20 to adjust the phase difference equal to or less than the sampling time interval. The phase adjustment device 20 is controlled as follows: First, a second automatic gain control device 21, which uses the same signal level as a reference, automatically controls the gain so as to adjust the amplitudes (amplitude amounts) of the digitized input signals S1 and S2.

[0033] A phase detector 22 detects the phase difference between the digitized input signals S1 and S2. Based on the detected phase difference, a reference signal generator 19 generates a reference signal containing information about the phase difference as an IQ signal. The phases of the input signals S1 and S2 can be aligned by aligning the input signals S1 and S2 with the reference signal in a phase adjustment device 20. In this case, by selecting a time constant that does not affect the other input signal S2 in response to changes in the signal state, such as the phase and amplitude, of one input signal S1, it is possible to align the delay, phase, and amplitude of the two input signals S1 and S2. The order in which the phases and amplitudes of the input signals S1 and S2 are aligned may be different from (reverse) the order described above.

[0034] The digital signals of the transmission systems L1 and L2, which have been adjusted in delay, phase, and amplitude as described above, are output via a combiner / selector 23. The combiner / selector 23 can be of a selective switching type that selects and outputs the digital signals transmitted through one of the transmission systems, or of a combining type that combines and outputs the digital signals transmitted through both transmission systems so as to obtain the best quality.

[0035] 1, the baseband signal output from the combining / selecting device 23 is converted into an analog signal by the digital-to-analog converting device 24, and the analog signal is adjusted to a desired level by the third automatic gain control device 25. The order of the digital-to-analog converting device 24 and the third automatic gain control device 25 may be reversed (or inverted).

[0036] In FIG. 1, the frequency conversion device 11 and the band elimination filter device 13 are configured to process only a specific signal, but in the signal receiving method of the present invention, these may be excluded and a configuration may be adopted in which a plurality of signals are processed.

[0037] In FIG. 1, after conversion to a digital signal by analog-to-digital converter 14, it is quadrature demodulated to an IQ (In-phase, Quadrature) baseband signal by quadrature demodulator 15. However, in the receiving method of the present invention, it is also possible to use a configuration in which quadrature demodulation is performed on an analog signal, and the I signal and Q signal are converted to digital signals by two analog-to-digital converters.

[0038] (Signal Receiving Method Embodiment 2: When Using the Signal Receiving Device of FIG. 2) As an embodiment of the signal receiving method of the present invention, the case of diversity reception using the signal receiving device of Fig. 2 will be described below as an example. The configurations and operations of 11 to 16 and 19 to 25 in Fig. 2 are the same as those of the first embodiment, so their description will be omitted.

[0039] 2 differs from embodiment 1 (FIG. 1) in that a storage device (delay device) 17a is provided only in one transmission system L1, and that a demodulator 101 and a signal quality measuring device 102 are added after the orthogonal demodulator 15. Therefore, in FIG. 2, a digital signal quadrature-demodulated by the orthogonal demodulator 15 is input to the demodulator 101, demodulated by the demodulator 101, measured by the signal quality measuring device 102, and then input to the combining / selecting device 23, and the digital signal is output in a selection or combining manner, as in embodiment 1. In this case, signal quality is measured based on the demodulated original data (signal) or data (signal) in the middle of demodulation, simultaneously with diversity reception, combining, or selection, so that degradation or a trend in signal quality can be measured and calculated instantaneously. Therefore, before the signal completely deteriorates and affects the video, it is possible to determine the ratio in the case of combining, or to determine and select the system in the case of selection.

[0040] The signal quality measuring device 102 is capable of measuring various qualities that vary depending on the demodulation process, such as input power, signal-to-noise ratio (SNR), modulation error ratio (MER), bit error ratio (BER), error vector magnitude (EVM), complementary cumulative distribution function (CCDF), and multipath based delay profile.

[0041] (Selection method and synthesis method) In the present invention, whether to use the selection method as shown in Fig. 1 or the combination method as shown in Fig. 2 can be determined based on an optimum index. For example, the input level and SNR of the input signal can be measured and used as indices, and when the input level is high but the SNR is low, a selection method configuration can be used. Alternatively, a combination method can be used in which MER and BER are used as indices, synchronization is achieved with the one with the higher BER, and the level ratio of the one with the worse MER is reduced to perform combination.

[0042] Quadrature demodulated signal brainThat is, by inputting a signal from an undelayed transmission system to the delay device 17a and a signal from a delayed transmission system to the other transmission system, the delay amounts of both transmission systems can be made equal at the sampling interval. The operation of the delay device 17a will now be described. For example, if the delay device 17a has an address numbered 1000 and the bit storage capacity per address is 32 bits, and if, for example, one digital signal sampled at 10 MHz in the analog-to-digital conversion device 14 is quadrature-demodulated by the quadrature demodulation device 15 and each IQ signal is 16 bits, the most significant 16 bits of one address are designated as an I signal and the least significant 16 bits are designated as a Q signal, the IQ signal can be stored at each address. Since the delayed transmission system signal does not have a delay device 17a, it is output at a relative address of 0. If the undelayed system signal arrives at the delay device 17a first and is stored and not output until the delay device 17a reaches address 1000, it will be output simultaneously with the delayed system signal at relative address 0. Since the non-delayed signal is output with a delay of 1000 samples, it is possible to output it with a time delay of 100 usec. The selection of signals to be input to the delay device 17a and signals not to be input can be performed by the delay device 17a.

[0043] For example, if 1000 samples are held and the address to be output is set to 500, it is possible to configure the output to be delayed by 50 usec.

[0044] (Signal Receiving Method Embodiment 3: When Using the Signal Receiving Device of FIG. 3) A third embodiment of the present invention will be described with reference to Fig. 3. In Fig. 3, the configurations and operations of 11 to 17a, 19 to 25, and 101 to 102 are the same as those of the second embodiment (Fig. 2), and therefore a description thereof will be omitted.

[0045] 3 differs from the second embodiment (FIG. 2) in that delay devices 17a and 17b are provided in the transmission systems L1 and L2, respectively, and that a combining and selecting control device 103 is provided.

[0046] 3, the output of signal quality measurement device 102 is input to combining / selecting device 23, which can switch between a combining method and a selection method depending on the output result. For example, when the output result of signal quality measurement device 102 indicates that the signals of all transmission systems are approaching a state where they will affect the receiver and the signal quality is unstable, combining / selecting device 23 in FIG. 3 can select a combining method to calculate a combining ratio from the signal quality measurement result so that the signal quality after combining will be maximized. For example, in a transmission system in which the signal quality of one signal is good and the signal quality of the other signal is degraded to the point where it will affect the receiver, alternately, selecting a selection method can ensure that the selected signal is always a good signal.

[0047] In the embodiment of FIG. 2, the non-delayed signal is input to the delay device 17a. In this case, if it is unclear which signal is not delayed, the delays of the signals on the transmission lines L1 and L2 may not match. In FIG. 3, by providing delay devices 17a and 17b on both transmission lines L1 and L2, the memory size increases, but it is possible to adjust the delays of multiple input signals by delaying one signal relative to the other, or by delaying the signals on both transmission lines. For example, if there are three signals (not shown), the signal on transmission line L1 is the most delayed. If the signals on transmission lines L2 and L3 also have different delays, the addresses of the delay devices for each transmission line can be selected separately.

[0048] For example, if there are signals from three transmission systems (not shown), and transmission system L2 requires an address of 250 relative to the delay of the signal from transmission system L1, and transmission system L3 requires an intermediate delay slightly slower than address 250, then by setting the sampling frequencies of delay device 17a and delay device 17b to 10 MHz for delay device 17a and 20 MHz for delay device 17b, and setting the address of delay device 17b to 501, it is possible to achieve a delay that is half the delay of the 10 MHz sampling frequency.

[0049] If signal quality is measured using an external quality measurement device, there is a problem that the switching operation of the combining / selecting device 23 between combining and selecting is delayed, which may affect the video. However, in the present invention, the signal quality measurement device 102 is located inside the signal receiving device, so this problem can be solved.

[0050] (Signal Receiving Method Embodiment 4: When Using the Signal Receiving Device of FIG. 4) A description will be given of a case where the fourth embodiment of the present invention is performed using the signal receiving device of Fig. 4. In Fig. 4, the configurations and operations of 11 to 17a, 19 to 25, and 101 to 103 are the same as those of the third embodiment, and therefore a description thereof will be omitted.

[0051] The differences between Figure 4 and embodiment 3 (Figure 3) are that the demodulation device 101 and signal quality measuring device 102, which are provided in both of the two transmission systems L1 and L2 in Figure 3, are provided only in one of the transmission systems L1, and the output of the orthogonal demodulation device 15 of the other transmission system L2 is input to the demodulation device 101 of the transmission system L1, that there is only one delay device 17a and four switching devices 18a to 18d are provided, and that a difference detection device 201, an averaging device 202, a storage device control device 203, a difference minimum storage value storage device 204, and a storage device storage value switching device 205 have been added.

[0052] In the signal receiving device of Figure 3, delay devices 17a and 17b must be installed in the two transmission systems L1 and L2, so the number of delay devices also increases as the number of transmission systems increases. With a large number of transmission systems, the storage capacity (number of addresses) per delay device 17a and 17b must be reduced, which can lead to insufficient storage capacity when a long delay is required. In Figure 4, this problem is solved by using a configuration in which one delay device 17a is shared between the two transmission systems L1 and L2. This sharing method can also be applied to cases with three or more transmission systems. In that case, the delay is first adjusted using one delay device 17a that shares the delay of the two transmission systems, and then the delay can be adjusted using a delay device installed in a new transmission system.

[0053] In Fig. 4, the output of the quadrature demodulator 15 of the transmission system L1 is input to the switching device 18a, and the output of the quadrature demodulator 15 of the transmission system L2 is input to the switching device 18b. For example, if the non-delayed transmission system is L1, the output of the switching device 18a is input to the storage device (delay device) The output of switching device 18b is input to switching device 18d. The output of storage device 17a is input to switching device 18c and switching device 18d. Switching device 18c receives input from both switching device 18a and storage device 17a and can select either one. Switching device 18d receives input from both storage device 17a and switching device 18b and can select either one. Because delayed L1 is input to storage device 17a, switching device 18c selects the input from storage device 17a and switching device 18d selects the input from switching device 18b, so that transmission line L2 can be output at address 0 without delay, and transmission line L1 can be output with a delay corresponding to the number of addresses set.

[0054] 4 detects the difference between the signals of two transmission systems L1 and L2. For example, if the signal of one system is expressed as S1+N1 (S1 is the signal, N1 is the noise) and the signal of the other system is expressed as S2+N2 (S2 is the signal, N2 is the noise), the output result of the difference detection system 201 is (S1+N1)-(S2+N2).

[0055] 4 averages the output results of the difference detection device 201. It is known that when the output of the difference detection device 201 is averaged, the average value of the randomly obtained noise components N1-N2 becomes zero.

[0056] The storage device control device 203 in FIG. 4 waits until the value of the averaging device 202 becomes constant, and outputs the stored value (delay value) to the storage device 17a.

[0057] The minimum difference stored value storage device 204 in FIG. 4 stores the output value when the output value of the averaging device 202 is smallest, the stored value (delay value) at that time, and the transmission system input to the storage device 17a.

[0058] The storage device storage value switching device 205 in FIG. 4 switches the storage value (delay value) to be input to the storage device 17a to the storage device control device 203. Output of , the output of the minimum difference storage value storage device 204 is switched to the output of the minimum difference storage value storage device 204.

[0059] (Delay matching in Figure 4) The receiving device configured as shown in FIG. 4 uses the storage device control device 203 to calculate the time it takes for the output value of the averaging device 202 to become constant. (sampling time) While waiting, the stored value (delay value) is controlled, and the delay value when the output value of averaging device 202 is minimum and the transmission system input to storage device 17a at that time are stored in minimum difference stored value storage device 204. The stored delay value is switched by storage device stored value switching device 205 as the stored value to be input to storage device 17a, thereby making it possible to match the delay difference between the two signals. This operation will be explained based on the flowchart in Fig. 5.

[0060] (Explanation of the operation of Figure 4 using the flowchart of Figure 5) (1) Under control (not shown) of the storage device storage value switching device 205 in Fig. 4, the delay value input to the delay device 17a is switched to the number of addresses determined by the output of the storage device control device 203 (S1 in Fig. 5). (2) Switching device 18a and switching device 18b are used to input one signal to delay device 17a. to Switch (S2 in Figure 5). (3) The storage device control device 203 outputs a delay value of 0 (S3 in FIG. 5). (4) The storage device control device 203 waits until the output value of the averaging device 202 is sufficiently stabilized (S4 in FIG. 5). (5) The minimum difference storage value storage device 204 stores the output value of the averaging device 202, the stored delay value 0 (initial value), and the transmission system input to the delay device 17a (S5 in FIG. 5). (6) The storage device control device 203 outputs a stored value of 1, which is the previous stored value of 0 plus 1. (7) The minimum difference stored value storage device 204 waits for a time period until the output value of the averaging device 202 becomes constant (S7 in FIG. 5). If the output value at that time is smaller than when the stored value was 0, the output value of the averaging device 202, stored value 1, and the transmission system input to the delay device 17a are stored (S8, S9 in FIG. 5). If the output value of the averaging device 202 is larger than when the initial value was 0, the information stored in the averaging device 202 is not changed (S8, S10 in FIG. 5). (8) The operations (1) to (7) are repeated while changing the delay value until the value set in the storage device 17a is reached (S1 in FIG. 5). When the set value reaches the maximum address value (limit value), the operation ends.

[0061] (9) When one of the signals reaches a set value through the above operation, the other signal is input to delay device 17a via switching device 18a and switching device 18b, the output of storage device control device 203 is returned to the stored value 0, and the same operations as those in (1) to (7) above are performed (S12, S13, S14 in FIG. 5). (10) When the operation of the other signal is completed, the minimum difference storage value storage device 204 stores the storage value at which the output of the averaging device 202 is minimum and the transmission system at that time. This information is stored in, for example, a non-volatile memory.

[0062] (11) Under the control of the storage device storage value switching device 205, the storage value input to the delay device 17a is switched to the storage value saved in the minimum difference storage value storage device 204 (S15 in FIG. 5). (12) The switching devices 18a and 18b switch to the system stored in the minimum difference storage value storage device 204 (S16 in FIG. 5).

[0063] According to the embodiment of FIG. 4, regardless of the signal modulation method or signal-specific characteristics, a complex circuit such as a demodulation circuit is not required, and delay can be matched simply by adjusting the signal amplitude and phase.

[0064] The above operation may be performed by other procedures as long as it is possible to search for a stored value that minimizes the output value of averaging device 202 or a value that minimizes the error between input signals S1 and S2. For example, the delay and phase may be adjusted so that the amplitude distribution of one signal and the amplitude distribution of the other signal are the same, and the values ​​may be stored and adjusted.

[0065] For example, if it is obvious that one signal is delayed, only the other signal needs to be delayed. The number of steps of the stored value may be changed, or the condition below the threshold may be set as the minimum value.

[0066] In all of the above embodiments, the delay, amplitude, and phase of two signals are adjusted at low cost to produce the same signal, so that signal continuity can be maintained when combining / selecting input signals S1 and S2, and signals can be combined / selected without affecting the receiver, regardless of the signal modulation method. [Industrial Applicability]

[0067] The signal receiving method and signal receiving device of the present invention can also be used as a signal relay method and a signal relay device. The present invention can accommodate three or more transmission systems by connecting multiple transmission systems in cascade or parallel, enabling diversity reception of three or more signals. In the case of cascade connection, one of two transmission systems L1 and L2 is first selected, the selected transmission system is designated as L2', and then either that transmission system L2' or a third transmission system L3 is selected, thus enabling selection in a tree structure. In the case of parallel connection, the quality of three or more transmission systems can be measured and the transmission system with the best quality can be selected. Since the commonly used combiner / selector 23 has up to two inputs, cascade connection is practical. The above embodiment is merely an example. The present invention can be modified within the scope that can solve the problem. [Explanation of symbols]

[0068] 1 input terminal 2 input terminals 11 Frequency conversion device 12 First automatic gain control device 13 Band-rejection filter 14 Analog-to-Digital Converter (ADC) 15 Quadrature demodulator 16 Oscillators 17 Delay adjustment device (delay device) 17a Memory device (delay device) 17b Memory device (delay device) 18a~18d Switching device 19 Reference signal generator 20 Phase Adjustment Device 21 Second automatic gain control device 22 Phase detector 23 Composition / Selection Device 24 Digital-to-analog conversion device 25 Third automatic gain control device 101 Demodulator 102 Signal Quality Measuring Device 103 Composite Selection Control Device 201 Differential detection device 202 Averaging device 203 Storage device control device 204 Differential Minimum Memory Value Storage Device 205 Storage device storage value switching device S1 Input signal 1 S2 Input signal 2 L1 transmission system L2 transmission system

Claims

1. A signal receiving method for diversity receiving two or more radio waves or signals arriving through different systems using two or more receiving devices, Two or more diversity-received signals are transmitted via separate transmission systems, converting the frequency of the received signal transmitted through each transmission system to an intermediate frequency; The level of each signal after frequency conversion is controlled to a predetermined level, Convert each signal into a digital signal, Converting each signal into a baseband signal; Selecting and delaying one of the baseband signals and the other, and adjusting the phases of the delayed and non-delayed baseband signals to match a reference signal (reference signal); The amplitude of one phase-adjusted baseband signal is adjusted to match the amplitude of the other baseband signal; Detecting a phase difference between the amplitude-matched baseband signals, matching the phases based on the detected phase difference, and selecting and outputting a baseband signal transmitted through one of the transmission systems from among the two or more baseband signals whose amplitudes and phases have been matched. A signal receiving method comprising:

2. In a signal receiving device that performs diversity reception using two or more receiving devices to receive two or more radio waves or signals arriving through different systems, two or more transmission systems for separately transmitting two or more diversity-received received signals; a frequency converter for converting the frequency of each received signal transmitted through each transmission system into an intermediate frequency; a first automatic gain control device that controls each of the frequency-converted received signals to a predetermined level; and an analog-to-digital conversion device that converts each of the received signals controlled to the predetermined level into a digital signal. a quadrature demodulator for converting the digital signal into a baseband signal; a delay device that delays the baseband signal after quadrature demodulation to reduce the delay difference between signals of two or more transmission systems; a switching device that switches between a signal to be input to the delay device and a signal not to be input; a reference signal generator for generating a reference signal for phase adjustment; a phase adjustment device for adjusting the phases of baseband signals transmitted through two or more transmission systems to a reference signal; a second automatic gain control device that adjusts the amplitude of one baseband signal phase-adjusted by the phase adjustment device and the amplitude of the other baseband signal; a phase detection device that detects a phase difference between one baseband signal and the other baseband signal whose amplitudes have been adjusted by the second automatic gain control device, and inputs the detected phase difference information to a reference signal generator so that a reference signal including the phase difference information is generated from the reference signal generator; a combining / selecting device for selecting and outputting a baseband signal transmitted through any one of the transmission systems from among the baseband signals controlled by the second automatic gain control device; A signal receiving device characterized by:

3. In a signal receiving device that performs diversity reception using two or more receiving devices to receive two or more radio waves or signals arriving through different systems, two or more transmission systems for separately transmitting two or more diversity-received received signals; a frequency converter for converting the frequency of each received signal transmitted through each transmission system into an intermediate frequency; a first automatic gain control device that controls each of the frequency-converted received signals to a predetermined level; and an analog-to-digital conversion device that converts each of the received signals controlled to the predetermined level into a digital signal. a quadrature demodulator for converting the digital signal into a baseband signal; a delay device that delays the baseband signal after quadrature demodulation to reduce the delay difference between signals of two or more transmission systems; a switching device that switches between a signal to be input to the delay device and a signal not to be input; a reference signal generator for generating a reference signal for phase adjustment; a phase adjustment device that adjusts the phase of a baseband signal that is quadrature demodulated by the quadrature demodulator and transmitted through two or more transmission systems to a reference signal; a second automatic gain control device that adjusts the amplitude of one baseband signal phase-adjusted by the phase adjustment device and the amplitude of the other baseband signal; a phase detection device that detects a phase difference between one baseband signal and the other baseband signal whose amplitudes have been adjusted by the second automatic gain control device, and inputs the detected phase difference information to a reference signal generator so that a reference signal including the phase difference information is generated from the reference signal generator; a demodulation device that demodulates the baseband signal that has been quadrature demodulated by the quadrature demodulation device; a signal quality measuring device capable of measuring the quality of a baseband signal demodulated by the demodulation device or a baseband signal in the middle of demodulation; a combining / selecting device that combines two or more baseband signals whose amplitudes have been adjusted by the second automatic gain control device based on the measurement result of the signal quality measuring device so as to obtain the best signal quality and outputs the combined signal; A signal receiving device characterized by:

4. 4. The signal receiving device according to claim 3, A delay device is provided in any one of two or more transmission systems. A signal receiving device characterized by:

5. 5. The signal receiving device according to claim 2, Between the second automatic gain control device and the delay device, a difference detection device that detects a difference in amplitude of baseband signals transmitted through two or more transmission systems; an averaging device for averaging the detected amplitude differences; a delay device control device that can control the value stored in the delay device while waiting for a time until the output value of the averaging device becomes constant, stores the output of the averaging device, and outputs the stored value; a differential minimum stored value storage device that stores the minimum output value obtained by averaging in the averaging device as a stored value (delay amount), can store and save the transmission system input to the delay device, and can adjust the delay difference of two or more baseband signals by inputting the stored stored value (delay amount) to the delay device; a delay device delay value switching device that switches the storage value (delay amount) to be input to the storage device between the delay value stored in the differential minimum delay value storage device and the delay value stored in the delay device control device; A signal receiving device characterized by:

6. 6. The signal receiving device according to claim 2, The delay device is shared between the two transmission systems. A signal receiving device characterized by:

7. 7. The signal receiving device according to claim 2, a digital-to-analog converter for converting the digital signal output from the synthesis / selection device into an analog signal; a third automatic gain control device that adjusts the digital-to-analog converted analog signal to a desired signal level; A signal receiving device characterized by:

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