JP2011139202A - Reception device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reception device which can rapidly search an optimum value of a control signal to correct the deviation of a tuning frequency of an antenna caused by an influence of an object adjacent to the reception device, and can correct the deviation of the tuning frequency by following a change in the influence of the adjacent object even if the influence has been changed. <P>SOLUTION: An arithmetic part 104 identifies an change amount and a change direction of a tuning frequency of an antenna 101 changed by an object adjacent to the antenna 101, previously limits a range of a value of a control signal to be searched when searching an optimum value of the control signal, corrects the deviation of the tuning frequency of the antenna 101 by rapidly executing the search, and always corrects the deviation of the tuning frequency by following the change of the adjacent object by detecting the change of the adjacent object. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a portable receiving device incorporating an antenna.

  In portable receivers, there is a demand for downsizing an antenna and incorporating it in a housing in order to improve design and reduce the risk of antenna damage. Therefore, by using a tunable antenna with a variable frequency at which the antenna gain is maximized (hereinafter referred to as tuning frequency), the antenna tuning frequency is appropriately adjusted to the frequency desired by the terminal user to achieve high gain. In addition, a built-in antenna capable of broadband reception has been realized.

  The tunable antenna uses the antenna characteristic impedance adjustment circuit to adjust the characteristic impedance of the antenna to a predetermined value, thereby matching the tuning frequency with the frequency desired by the terminal user. The characteristic impedance adjustment circuit is controlled by a control signal. However, the characteristic impedance of the antenna changes under the influence of an object close to the receiving apparatus, and a phenomenon occurs in which the tuning frequency of the antenna deviates from the frequency that the terminal user desires to receive. In particular, in a portable receiving device, a form in which it is used by hand is conceivable. In this case, since the receiving device is used close to the human body of the user, the receiving device is placed on a desk and used. Compared with the case of, the characteristic impedance of the antenna changes due to the influence of the human body. When such a shift occurs, the antenna gain at the frequency that the terminal user desires to receive decreases, and the reception sensitivity deteriorates.

  In order to solve this deterioration, Patent Document 1 discloses a method of monitoring a received signal power (Received Signal Strength Indicator, hereinafter abbreviated as “RSSI”) and searching for a value of a control signal having a maximum RSSI. ing. According to this, even when the impedance mismatch with the antenna occurs due to the influence of the nearby human body, the antenna tuning frequency changes, and the original antenna gain cannot be obtained and the RSSI is lowered, the control signal for matching the impedance is reduced. The RSSI can be recovered by automatically searching for the optimum value.

JP 2007-13890 A

  However, in the method for searching for the optimum value of the control signal, the influence of an adjacent object changes, for example, when the receiver is held in hand and the terminal is held in hand. When the characteristic impedance of the antenna changes, there is a problem that the optimum value of the control signal changes.

  In view of the above points, the object of the present invention is to always optimize the operation of the antenna even when the influence of an object close to the antenna changes and the optimal value of the control signal for adjusting the tuning frequency of the antenna fluctuates. It is to provide a receiving device that maintains a state.

  The receiving apparatus according to the present invention determines a range in which a value of the control signal that provides the best signal quality or signal quality received by the receiving apparatus can be present as a search range, and the reception state is determined from the search range. Alternatively, a search means for searching for the value of the control signal with the best signal quality according to a predetermined procedure is provided.

  Then, the amount of change and direction of the tuning frequency of the antenna that changes depending on the object close to the antenna is specified, and the control signal to be searched when searching for the value of the control signal that provides the best reception state or signal quality Is limited, and the above search is executed at high speed to correct the deviation of the tuning frequency of the antenna.

  Also, if it is necessary to change the optimal setting value of the control signal by detecting a change in the influence due to an object close to the antenna, the optimal setting value is appropriately searched and the control signal value is always set to the optimal value. Let it be maintained.

  According to the receiving apparatus of the present invention, it is possible to correct the antenna tuning frequency shift by searching for the optimum value of the control signal at high speed without providing any additional circuit, and to detect an object close to the antenna. The antenna operation can always be maintained in an optimum state even when the optimum value of the control signal for adjusting the tuning frequency of the antenna fluctuates due to a change in the influence of the antenna.

It is the block diagram which showed one Example of the receiver by this invention. FIG. 3 is a block diagram illustrating an embodiment of a tuning frequency adjustment unit according to the present invention. It is a change characteristic figure of the tuning frequency with respect to a control signal value. It is a change characteristic figure of CNR with respect to a control signal value. It is a flowchart of the algorithm which searches for the control signal value in which CNR becomes the maximum. It is a change characteristic figure of the tuning frequency with respect to each control signal value, when there is no human body influence and when there is no. It is a change characteristic figure of CNR with respect to a control signal value. It is a flowchart of the algorithm which searches for the control signal value in which CNR becomes the maximum at high speed. 4 is a flowchart of an algorithm for searching for a control signal value according to the present invention. It is the block diagram which showed one Example of the receiver by this invention. It is the figure which showed an example of the housing | casing shape change of a terminal. It is a figure which shows an example of a CNR measurement result. It is a flowchart which shows the procedure which measures CNR. It is a flowchart of the algorithm which determines the necessity of the re-search start of a control signal optimal value. It is a change characteristic figure of CNR with respect to a control signal value. 6 is a flowchart showing another embodiment of an algorithm for searching for a control signal value according to the present invention. It is a change characteristic figure of CNR with respect to a control signal value. 6 is a flowchart showing another embodiment of an algorithm for searching for a control signal value according to the present invention. It is a change characteristic figure of CNR with respect to a control signal value. It is another change characteristic view of CNR with respect to a control signal value. It is the block diagram which showed one Example of the receiver by this invention. 4 is a flowchart of an algorithm for searching for a control signal value according to the present invention. It is a flowchart of the algorithm which determines the necessity of the re-search start of a control signal optimal value.

  Embodiments of a receiving apparatus according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing an example of an embodiment of a receiving apparatus according to the present invention. The details of the embodiment shown in FIG. 1 when the present invention is applied to a terrestrial digital broadcast receiver will be described below.

  Digital terrestrial broadcasting implemented in Japan uses a frequency band from 470 MHz to 770 MHz divided into 50 channels, and the frequency bandwidth of one channel is 6 MHz. When considering incorporating an antenna in a housing, it is necessary to reduce the size of a mobile terminal or a mobile terminal, but the gain of the antenna decreases due to the miniaturization. On the other hand, since the gain can be increased as the reception frequency bandwidth of the antenna is narrowed, the reception frequency bandwidth of the antenna can be narrowed and the frequency (tuning frequency) at which the antenna gain is maximized can be varied. The structure is made to function as a tunable antenna. As a result, high gain and wide band reception can be realized by appropriately adjusting the tuning frequency to the frequency desired by the terminal user.

  A user of a terminal equipped with a receiving apparatus according to the present invention inputs a frequency channel desired to be viewed into the terminal by a key operation or the like. Based on this input information, the receiving apparatus selects and receives the frequency channel that the user desires to view.

  The receiving apparatus of this embodiment includes an antenna 101, a tuning frequency adjustment unit 102, a receiving circuit unit 103, and a calculation unit 104. The calculation unit 104 includes a storage unit 105.

  The antenna 101 can receive a radio wave transmitted by a transmission device (not shown), and outputs a high-frequency signal corresponding to the radio wave received by the antenna to the tuning frequency adjustment unit 102. The tuning frequency adjustment unit 102 outputs the high frequency signal input from the antenna 101 to the reception circuit 103. The receiving circuit 103 selects a frequency (that is, a receiving frequency) desired to be received, which is determined in accordance with a key operation of the terminal user, from among the high frequency signals input from the tuning frequency adjusting unit 102, and a baseband signal. Then, digital demodulation and error correction are performed, and a TS signal (transport stream signal) is output. At the same time, as the signal quality of the selected high-frequency signal, the average power of the carrier in the carrier band of the high-frequency signal CNR (Carrier to Noise Ratio), which is the ratio of noise power to noise.

  The calculation unit 104 reads the CNR measured by the reception circuit 103. In this embodiment, CNR is used. In addition to CNR, MER (Modulation Error Ratio) representing how much the ideal symbol position of the constellation is shifted from the actual symbol position is demodulated. Other indicators that can be measured by the receiving circuit 103 such as BER (Bit Error Rate) representing the ratio between the number of error bits of the digital signal and the total number of bits, or the signal strength of the received signal may be used. .

  In addition, the calculation unit 104 outputs a control signal for controlling the tuning frequency adjustment unit 102. The control signal output from the calculation unit 104 is input to the tuning frequency adjustment unit 102. The tuning frequency adjustment unit 102 can change the tuning frequency of the antenna 101 by changing the characteristic impedance of the antenna 101 in accordance with the input control signal. By this operation, the antenna 101 and the tuning frequency adjustment unit 102 function as a tunable antenna whose tuning frequency can be varied. The storage unit 105 records the CNR value acquired by the calculation unit 104 from the reception circuit 103, and the calculation unit 104 can use the value as necessary.

  FIG. 2 is a block diagram illustrating an example of the tuning frequency adjustment unit 102 according to this embodiment. Details of the tuning frequency adjustment unit 102 shown in FIG. 2 will be described below.

The tuning frequency adjustment unit 102 includes a capacitive element 201, a variable capacitive element 202, and a resistor 203. A control signal input from the calculation unit 104 to the tuning frequency adjustment unit 102 controls the capacitance value of the variable capacitance element 202. In this embodiment, the variable capacitance element 202 is constituted by a variable capacitance diode. The control signal is a reverse bias voltage applied to the variable capacitance diode, and changes the capacitance value by changing the voltage value. By changing the capacitance value of the variable capacitance element 202, the characteristic impedance of the antenna 101 is changed, and the tuning frequency of the antenna 101 is changed.
The above is the basic configuration of the receiving apparatus shown in this embodiment.

Next, the characteristics of the antenna shown in this embodiment will be described with reference to FIGS.
FIG. 3 is a characteristic diagram showing how the tuning frequency of the antenna 101 changes depending on the value of the control signal. The horizontal axis of FIG. 3 represents the value of the control signal input from the calculation unit 104, and the vertical axis represents the tuning frequency of the antenna 101. The frequency of the frequency channel that the user desires to view is assumed to be fch. In FIG. 3, the value of the control signal (reverse bias voltage applied to the variable capacitance diode) takes a value between the lower limit value Vmin and the upper limit value Vmax, and the value of the control signal is Vch. 101 shows that the tuning frequency of 101 matches the reception frequency fch. The lower limit value Vmin and the upper limit value Vmax correspond to, for example, 470 MHz and 770 MHz which are frequency bands of terrestrial digital broadcasting. Alternatively, it is set wider than the frequency band of digital terrestrial broadcasting in consideration of margins due to performance variations of mounted components and substrate manufacturing variations.

  FIG. 4 is a characteristic diagram showing an example of CNR (value of ratio between average power of carrier wave and noise power) with respect to the value of the control signal in the embodiment shown in FIG. The horizontal axis of FIG. 4 represents the value of the control signal, and the vertical axis represents the value of CNR. FIG. 4 shows that the value of CNR changes by changing the value of the control signal. Further, FIG. 4 shows that when there is no object close to the receiving apparatus, the value of the control signal with the maximum CNR value is Vch, but when there is an object, the CNR value is maximum. The optimum value of the control signal to be a value represents not Vch but Vbest. The reason why the optimum value changes is that the tuning frequency has changed due to the influence of an object close to the receiving device, and therefore the value of the control signal that matches the frequency fch of the frequency channel that the user desires to view and the tuning frequency is It is because it became Vbest instead of Vch.

Next, details of the operation of the calculation unit 104 will be described.
The calculation unit 104 uses a range between Vmin and Vmax as a search range, and searches the search range for the value Vbest of the control signal having the maximum CNR. By this search, an optimum value of the control signal can be obtained, and it is possible to correct a deviation between the tuning frequency of the antenna 101 and the reception frequency even when there is an influence of an object close to the reception device.

The procedure for executing this search will be described with reference to the flowchart of FIG.
In the flowchart shown in FIG. 5, in step S501, the calculation unit 104 sets the value of the control signal (hereinafter referred to as Vctrl) to Vmin which is the lower limit value of the search range.
Step S502 is an end determination, and it is determined whether or not the value of Vctrl has exceeded Vmax, which is the upper limit value of the search range. If the result of the determination is Yes, the series of processing ends. If the result of the determination is No, the process proceeds to step S503. In S503, the CNR of the signal received by the receiving circuit 103 is measured, and the arithmetic unit 104 reads the measured CNR. In step S504, the value of Vctrl is increased by a predetermined amount t to obtain a new Vctrl, and the process returns to step S502. Here, t is an arbitrary real value (for example, 0.1 V or 0.5 V). Thereafter, the operations up to S504 are repeated until the end determination in S502 is established.

By executing the above-described processing, the CNR for the control voltage value within the search range can be obtained, and Vbest, which is the value of the control signal that maximizes the CNR value, is obtained by comparing the obtained results. Can do. Although the procedure for calculating Vbest is not described in FIG. 5, as part of the processing in step S503, the CNR measured in step S503 is stored in the storage unit 105 provided in the calculation unit 104, and step S502, Each time a series of loop operations of S503 and S504, the value of the control voltage value Vctrl that maximizes the CNR is updated, and the higher CNR value and the control voltage value Vctrl at that time are successively stored to obtain Vbest. Or the CNR values corresponding to all the values of Vctrl set in steps S501 and S504 are all stored in the storage unit 105 in step S503 together with the value of the control voltage value Vctrl, and step S502 is completed. The control power that can obtain the maximum value among the CNRs stored in the storage unit after the determination is established. There is a method to Vbest this request the value Vctrl. After Vbest is obtained, the operation unit 104 sets the value Vctrl of the control signal to Vbest, so that the tuning frequency of the antenna 101 matches the reception frequency, so that a stable reception operation is realized.
In step S504, t is used as an increase amount for increasing the value of Vctrl. However, by reducing the value of t, the resolution at the time of obtaining the value of Vbest can be reduced, and a more detailed value of Vbest. Can be obtained. However, the minimum resolution for setting Vctrl is the lower limit value of t. In addition, the accuracy of obtaining Vbest is increased by increasing the value of t. However, the time required until the series of loop operations including steps S502, S503, and S504 is completed can be reduced, and Vbest is obtained more quickly. It becomes possible. When searching for the optimum control voltage Vbest, the search is initially made with a large increase amount t to narrow the range of the control voltage value Vctrl where Vbest exists, and then the range of the control voltage value Vctrl is reduced with a small increase amount t. It is also possible to search for Vbest.

  Here, the procedure for increasing the value of Vctrl to Vmax using Vmin as the initial value has been described. However, if the CNR for the control voltage value within the search range can be obtained, other steps such as decreasing Vmax to Vmin using the initial value as Vmax are possible. It is obvious that the same effect can be obtained by the procedure.

  In the procedure in which the receiving apparatus 103 measures the CNR in step S503, the measurement may use a result obtained by measuring only once after Vctrl is set to an arbitrary value. However, when the measurement error included in the measurement result is large, the operation is based on the wrong CNR value, and it is necessary to consider that the optimum Vbest cannot be obtained. There is a need to reduce.

  The graph of FIG. 12 is an example of a CNR measurement result. As shown in FIG. 12, the CNR measurement results have different values for each measurement. The difference between the maximum value and the minimum value is a measurement error. The number of measurements (horizontal axis) is n, and by taking the average value of the data for n times, a more probable value can be obtained using only one measurement result. I understand that.

  The procedure of CNR measurement in step S503 in FIG. 5 (the same applies to FIG. 8 described later) will be described with reference to FIG. Step S1301 is the start of the CNR measurement procedure, and a variable n representing the number of measurements is set to 1. In step S1302, the CNR of the received signal is measured by the receiving circuit 103 in FIG. The measured CNR value is read from the receiving circuit 103 by the arithmetic circuit 104 in step S1303. The arithmetic circuit 104 performs an averaging process on the read CNR value. Step S1304 is an end determination. If the number of measurements n reaches the predetermined number of measurements N, that is, if N measurements have been completed, the process proceeds to step S1307. If N measurements have not been completed, the process proceeds to step S1305. In step S1305, the process waits for a predetermined time so as to maintain the CNR measurement interval. In step S1306, the variable n indicating the number of measurements is incremented by 1, and the process returns to step S1303 to repeat the above operation. In step S1307, the average value for the predetermined N times obtained in the process of immediately preceding S1303 is recorded as the CNR value.

  The above processing shown in FIG. 13 is performed in the CNR measurement in step S503 in FIG. 5 (FIG. 8). The series of CNR measurement processing shown in FIG. 13 is performed every time Vctrl is changed in step S504 in the flowchart of FIG. 5 (FIG. 8).

  By the above average value calculation process, a more probable value using only one measurement result can be obtained. In the description here, the number of data is described as N. However, as N is increased, the probability of the calculated average value can be increased. Further, by reducing N, the time required for measurement can be shortened. In the present description, the object to be measured by the receiving circuit 103 in step S1302 has been described as CNR. However, the same operation is possible even when the measurement object is MER or BER. However, regarding the averaging process, it is necessary to consider arithmetic average, geometric average, etc. depending on the object. The number N of data measurements may be determined in advance, or when the average value changes below a certain threshold (however, the minimum value is determined separately), the average value changes between the maximum and minimum values. You may decide arbitrarily, such as when the difference is less than a certain amount. By making the value of N variable in this way, when the change amount of CNR is small, that is, when the measurement error in FIG. 12 is small, the calculation of the average value of CNR can be completed earlier, and the processing time is increased. Can be achieved. If the environment in which the receiving terminal is located is known in advance and the CNR measurement error range can be estimated, the value of N may be determined based on the error range. As an example, when the receiving terminal 102 knows that the receiving terminal is in a moving environment by processing such as obtaining the Doppler shift amount of the received signal in the receiving circuit 102, or when the received electric field strength is small and easily affected by external noise, etc. The error is also expected to increase. At this time, the probability of the CNR calculation result can be increased by sufficiently increasing the value of N. On the other hand, when it is known that the receiving terminal is in a stationary state, or when the received electric field strength is sufficiently large and the influence of external noise is small, it is expected that the CNR measurement error will be small. At this time, even if the value of N is reduced, the certainty of the CNR calculation result can be maintained. Thus, by making the value of N variable, an optimal operation can be realized according to the reception environment.

  Moreover, although the example which calculates | requires an average value was shown here, the median value of the median value of all the data measured N times, the mode value when a CNR value is represented by frequency distribution (for example, a numerical value of 0.5 step), etc. are averaged. It may be used instead of a value. Average value processing is easily affected by outliers, and if the CNR greatly deteriorates for a moment due to instantaneous interruption of the received signal or external noise, the average value of the CNR also greatly deteriorates, but by using the median value It is possible to make it less susceptible to outliers.

  Next, problems in this operation and countermeasures will be described. In the above description, there is a problem that it takes a long time to obtain Vbest by setting a search range between Vmin and Vmax and executing a search from this search range.

  Therefore, the amount and direction of change in the tuning frequency of the antenna due to the influence of an object close to the receiving device are specified, and the search range is narrowed. The object close to the receiving device is, for example, a human body of a terminal user who uses the receiving device shown in the present embodiment.

  Hereinafter, a method for narrowing the search range will be described. FIG. 6 shows the relationship between the control signal value and the tuning frequency of the antenna 101 in each case when the human body is not close to the receiving apparatus and when the human body is close. When the human body is not close to the receiving device, the tuning frequency of the antenna 101 matches the receiving frequency fch that the terminal user desires to view by setting the value of the control signal to Vch. When the antennas are close to each other, the tuning frequency of the antenna 101 changes (becomes lower) due to being equivalent to an increase in capacity, resulting in a deviation from the reception frequency. Here, the amount of change in the tuning frequency of the antenna 101 and the direction of the change (whether the tuning frequency becomes higher or lower) due to the proximity of the human body to the receiving device are investigated in advance. As a result of this investigation, it is known that when the reception frequency is, for example, 470 MHz, the amount of change in the tuning frequency does not exceed 100 MHz at the maximum, and the tuning frequency of the antenna 101 is generally low.

  The calculation unit 104 includes search range limiting means for narrowing the search range by using this fact. The calculation unit 104 does not set the search range between Vmin and Vmax, but a control signal value (reverse bias voltage value) that is larger than Vch by a control signal value amount that increases the tuning frequency of the Vch and the antenna 101 by 100 MHz. The search range is between. FIG. 7 shows how the search range is narrowed.

A procedure for executing a search when the search range is narrowed by the above-described method will be described with reference to the flowchart of FIG. In addition, the same code | symbol is described to the process similar to FIG.
8 differs from FIG. 5 in that step S801 is added and that the lower limit value of the search range is Vmin2 and the upper limit value is Vmax2.
In step S801, Vch is set to a value of Vmin2, and a value larger than Vch by a control signal value amount that makes the tuning frequency of the antenna 101 higher by 100 MHz is set to a value of Vmax2. All subsequent processing is the same as the processing in FIG. 5 described above.

  By executing the processing shown in FIG. 8, it is possible to search for Vbest which is the value of the control signal that maximizes the CNR value faster than the processing of FIG. Further, as can be seen from FIG. 7, since the control signal value that maximizes the CNR is included in the narrowed search range, the control signal value that maximizes the CNR can always be searched even if the search range is narrowed. is there.

  As described above, the amount of time required for searching is shortened by investigating the amount and direction of change in the tuning frequency due to the influence of the object close to the receiving device, for example, the human body, and narrowing the search range based on this investigation result. can do. Further, in this method, a tuning frequency shift can be corrected by searching for the optimum value Vbest of the control signal at high speed without providing any additional circuit. As a result, while searching for the optimum value of the control signal in the conventional receiving apparatus, the tuning frequency of the antenna remains shifted from the frequency that the terminal user desires to receive, and the search is completed. However, it is possible to shorten the search time by using this configuration, and the usability of the terminal can be improved.

  However, when the influence of an object close to the receiving terminal on the receiving terminal changes and the characteristic impedance of the antenna changes, the optimal value of the control signal may change. At this time, if the value of the control signal is once searched and set to Vbest, the reception characteristic is deteriorated. Therefore, it is necessary to search for the optimum value again. A control procedure taking into consideration the optimum value re-search, which is the main point of the present invention, will be described below.

  FIG. 9 is a flowchart for explaining the execution of the search for the optimum value. Step S901 is a state in which the operation of the TV viewing function is started, and this receiving apparatus is activated. When the receiving apparatus is activated, initialization setting and channel selection setting for the receiving circuit 103 in FIG. 1 are performed. If a broadcast signal is input to the receiving circuit 103, the television can be viewed. The value of the control signal output from the arithmetic unit 104 to the tuning frequency adjusting unit 102 is set to the control signal value of Vch shown in FIG. 4, assuming that there is no object close to the terminal when searching is not performed. . Here, the control signal value Vch is a value associated with an arbitrary reception frequency fch by the graph of FIG. 3, and fch is a frequency channel input by the user after starting the TV function, and the reception device is operating last. This is the frequency corresponding to the frequency channel that was sometimes selected or the frequency channel that was previously set as the initial value of the receiving terminal.

With respect to the setting of Vch at the time of starting the operation of the television viewing function in step S901, there is actually a possibility that there is an object close to the receiving device, so the optimum value of the control signal is searched for in step S902. As a result of S902, as described with reference to FIGS. 5 to 8, Vbest is obtained as the optimum value of the control signal. In response to this result, the calculation unit 104 sets the value of the control signal output to the tuning frequency adjustment unit 102 to Vbest, and matches the tuning frequency of the antenna 101 with the signal frequency that the user desires to view, as step S903. The normal viewing state is obtained.
Step S904 is an end determination. When the TV viewing function is turned off, this flowchart ends. If not turned off, the process proceeds to step S905.

In step S905, it is determined whether an object close to the terminal has changed. Although details of the operation in S905 will be described later, when it is detected that there is a change in an object close to the terminal, it is necessary to optimize the value of the control signal output from the calculation unit 104 to the tuning frequency adjustment unit 102. If it is determined that there is, the process proceeds to step S906, and the optimum value is re-searched. By performing the search again in S906, a new optimum value Vbest2 is obtained as the value of the control signal. Upon receiving this result, the calculation unit 104 sets the value of the control signal output to the tuning frequency adjustment unit 102 to Vbest2 and sets the antenna. The tuning frequency of 101 is matched with the signal frequency that the user desires to view, and the normal viewing state is set in step S903.
If no change is detected in the object close to the terminal in step S905, the search is not performed and the process returns to S903 and the normal viewing state is continued.

  By repeating the steps from S903 to S906, even if a change occurs in an object close to the terminal and the tuning frequency of the antenna 101 needs to be changed, a change in state is detected in step S905, and a new control is performed in S906. Since the signal value Vbest2 is searched, a stable television viewing state is always maintained.

  Hereinafter, the method for determining whether or not there is a change in an object close to the terminal in S905 will be described in detail. FIG. 10 is a block diagram showing an example of an embodiment of a receiving apparatus according to the present invention. Functional blocks having the same functions as those of the receiving apparatus shown in FIG. In FIG. 10, reference numeral 901 denotes an arithmetic unit provided with a storage unit, and 902 denotes a storage unit. The storage unit 902 records the CNR value acquired by the calculation unit 901 from the reception circuit 103, and the calculation unit 901 can use the value as necessary.

FIG. 14 is a flowchart showing in detail the determination method of S905 in FIG. In this flowchart, the value of the control signal is set to two different values, the reception state or signal quality at each value is measured, and it is determined whether to perform a re-search based on the comparison result is doing.
Step S1401 in FIG. 14 is a start of determination as to whether or not an optimum value search for the value of the control signal needs to be performed. At this time, since the user is in a normal viewing state, the optimum Vbest is set as the value of the control signal as the value of the control signal obtained in step S902 in FIG. 9 (about the value of the control signal). One set value). In step S1402, the calculation unit 901 reads the CNR measured by the reception circuit 103. The current CNR value is recorded as CNR1 in the storage unit 902 in the calculation unit 901. In step S1403, the calculation unit 901 sets Vch as the value Vctrl of the control signal (the other set value for the value of the control signal). As described above, Vch is a control signal value that is optimal for the reception frequency fch that the user desires to view when there is no object close to the receiving apparatus. In step S1404, the reception circuit 103 measures the CNR in a state where the value Vctrl of the control signal is set to Vch, and the calculation unit 901 reads the CNR value and records it as CNR2.

  In step S1405, CNR1 and CNR2 recorded in the storage unit 902 are compared. As a result of the determination in step S1405, if CNR1 is superior to CNR2, the state in which Vctrl is set to Vbest is excellent as the reception state. Therefore, in step S1407, the control signal value Vctrl is returned to Vbest. To finish the determination process. In this case, the determination in step S905 in the flowchart of FIG. 9 is No, the search is not performed, and the normal viewing is resumed.

  As a result of the determination in step S1405, if CNR1 is inferior to CNR2, there is a control signal value with better reception performance than the state in which Vctrl is set to Vbest. Therefore, an optimal control signal value is searched. There is a need. In this case, the determination in step S905 in the flowchart of FIG. 9 is Yes, and an optimal control signal value is searched.

  FIG. 15 is a characteristic diagram for explaining the present embodiment, and shows an example of the value of CNR with respect to the value of the control signal as in FIG. In FIG. 15, the horizontal axis represents the value of the control signal, and the vertical axis represents the value of CNR, and shows that the CNR value changes by changing the value of the control signal. Three characteristic curves are described. When there is no object close to the receiving apparatus, the characteristic curve 1501 is shown. The best CNR is obtained when the control signal value Vctrl is set to Vch. A characteristic curve 1502 indicates that there is an object close to the terminal and the influence thereof is large. At this time, the value of the control signal having the maximum CNR value is not Vch but Vbest. A characteristic curve 1503 indicates that an object close to the terminal exists but the influence thereof is not as great as that of the characteristic curve 1502. At this time, the value of the control signal having the maximum CNR value is Vbest2.

  The concrete state of the three characteristic curves will be described with reference to FIG. FIG. 11 shows a receiving terminal. In FIG. 11, reference numeral 1001 denotes a lid portion on which a liquid crystal display portion is mounted. Reference numeral 1002 denotes a main body, which is not shown but includes a receiving device including an antenna, a receiving circuit, etc. in addition to an input key arrangement. 11A shows when the lid body portion 1001 is in the open state, and FIG. 11B shows when the lid body portion 1001 is in the closed state, and is provided between the main body portion 1001 and the lid body portion 1002. It is possible to shift between both states by rotating the hinge portion. A characteristic curve 1501 in FIG. 15 is a state where there is no object close to the antenna of the terminal, and is a state shown in FIG. 11A and a state where the human body is not close. A characteristic curve 1502 in FIG. 15 is a state where an object having a large influence on the antenna such as a human body is close to the antenna of the terminal, and as an example, the main body 1002 with the terminal in the state of FIG. Is in a state of being held so as to cover. A characteristic curve 1503 in FIG. 15 does not affect as much as the human body, but there is an object close to the antenna, and as an example, the reception stored in the main body 1002 as shown in FIG. In this state, the lid 1001 is close to the apparatus.

  The relationship between the state of the terminal and each characteristic curve will be described in further detail. When the user starts the television function of the terminal, the terminal is in the state of FIG. 11A and is held by hand. The characteristic curve is 1502. In the flowchart of FIG. 9 showing the operation of the receiving apparatus, since step S902 is performed in the state of this characteristic curve 1502, the value Vctrl of the control signal is set to Vbest at which the maximum CNR is obtained on the characteristic curve 1502. Thereafter, when the user views the terminal in the state of FIG. 11B, the characteristic curve of FIG. 15 shifts to the state of 1503. However, the control signal value Vctrl remains set to Vbest. In the flowchart of FIG. 9 showing the operation of the receiving apparatus, when the process of step S905 is performed, more specifically, when the CNR is measured in the process of step S1402 of FIG. 14, CNR1 of FIG. In the process of S1404, CNR2 in FIG. 15 is observed as the CNR. As a result, since CNR1 <CNR2, the process proceeds to step S1406 on the flowchart of FIG. 14, and processing for searching for the optimum value of the control signal in step S906 of the flowchart of FIG. 9 is performed. Here, since it follows the characteristic curve 1503, Vbest2 is obtained as the control signal value Vctrl from FIG.

With the above operation, even when the television viewing state of the receiving terminal is different from the state immediately after the start of the television function, it is found that the state of the terminal has changed by operating according to the flowchart shown in FIG. A signal optimization process is performed to always maintain an optimal control signal value. In this way, stable TV viewing is always realized.
Even if the environment of the terminal is temporarily changed, such as when the terminal is held in hand and then returned to the original location, it may return immediately. Assuming such a case, it is possible to return to a fixed value of Vch which is the value of the control signal when the tuning frequency of the antenna matches the reception frequency without re-searching for the optimum value of the control signal. Can be one of the measures.
An example of the operation in this case is shown in FIG. In S2105 in FIG. 21, the same processing as S905 in FIG. 9 is performed, and when the result is Yes, in S2106, the control signal value Vctrl is returned to Vch.
FIG. 22 is a flowchart showing in detail the determination method of S2105 in FIG. Compared to FIG. 14, the processing in the case of Yes in S1405 is different, and processing for returning the control voltage value Vctrl to Vch is performed without performing a search. Since the re-search process is not performed, the process is less than that in the operation example shown in FIG. 9, and the operation speed can be increased.

  FIG. 16 is a flowchart for explaining a second embodiment of the receiving apparatus according to the present invention. An operation in which the operation according to the flowchart shown in FIG. 16 is adapted to the configuration of the block diagram shown in FIG. 10 will be described below.

  In FIG. 16, step S1601 is a state in which the operation of the TV viewing function is started, and this receiving apparatus is activated. In the activated state of the receiving apparatus, initialization setting and channel selection setting are performed for the receiving circuit 103 in FIG. 10, and when a broadcast signal is input to the receiving circuit 103, the television can be viewed. The value of the control signal output from the arithmetic unit 901 to the tuning frequency adjusting unit 102 is treated as no object close to the receiving apparatus in the initial state, and is set to the Vch control signal value shown in FIG. Here, the control signal value Vch is a value associated with an arbitrary reception frequency fch by the graph of FIG. 3, and as fch, the frequency channel input by the user after the TV function is activated, and the reception device is operating last. The frequency corresponding to the frequency channel selected at that time or the frequency channel set in advance as the initial value of the receiving terminal is set.

  However, since there may actually be an object (such as the user) that is close to the receiving apparatus, an optimal control signal value is searched for in step S1602. As a result of the search in S1602, Vbest is obtained as the optimum value of the control signal as described in FIG. In response to this result, the calculation unit 901 sets the value of the control signal output to the tuning frequency adjusting unit 102 to Vbest, and matches the tuning frequency of the antenna 101 with the signal frequency that the user desires to view. In step S1603, the receiving circuit 103 measures the CNR in this state, and the calculation unit 901 reads the CNR value and records it as CNR3 in the storage unit 902. Thereafter, the normal viewing state is set as step S1604. Step S1605 is an end determination, and when the TV viewing function is turned off, this flowchart ends. If not turned off, the process proceeds to step S1606.

  In step S1606, the receiving circuit 103 measures the CNR of the received signal again. The calculation unit 901 reads this CNR value and records it in the storage unit 902 as CNR4. In step S1607, it is determined whether an object close to the terminal has changed. Although details of the operation in S1607 will be described later, when it is detected that there is a change in an adjacent object, it is necessary to optimize the value of the control signal output from the arithmetic unit 901 to the tuning frequency adjustment unit 102. Determination is made, and the process proceeds to step S1608 to search for the optimum value. As a result of the search in S1608, a new optimum value Vbest2 is obtained as the value of the control signal. Upon receiving this result, the calculation unit 901 sets the value of the control signal output to the tuning frequency adjustment unit 102 to Vbest2 and sets the value of the antenna 101. The tuning frequency is matched with the signal frequency that the user desires to view, and the value of CNR3 is newly updated in step S1609, and the normal viewing state is set in step S1604.

If it is not detected in step S1607 that there is a change in an adjacent object, the search is not performed and the process returns to S1604 and the normal viewing state is continued.
By repeating the steps from S1604 to S1608, even if a change occurs in an object close to the terminal and the tuning frequency of the antenna 101 needs to be changed, a change in state is detected in step S1607, and a new control is performed in S1608. Since the signal value Vbest2 is searched, a stable television viewing state is always maintained.

  Hereinafter, the method for determining whether or not there is a change in the close object in S1607 will be described in detail. The calculation unit 901 calculates the absolute value of the difference between CNR3 and CNR4 recorded in the storage unit 902. A threshold value CNRth is set in advance, and when the difference between CNR3 and CNR4 is less than this threshold value CNRth, it is determined that there is no change in an object close to the antenna. When the difference between CNR3 and CNR4 exceeds CNRth, it is determined that there is a change in an object close to the antenna and a change has occurred in the tuning frequency of the antenna. Changes in the characteristic curve of the antenna at this time will be described with reference to FIG.

  FIG. 17 is a characteristic diagram for explaining the present embodiment, and shows an example of the value of CNR with respect to the value of the control signal as in FIG. In FIG. 17, the horizontal axis represents the value of the control signal, and the vertical axis represents the value of CNR, indicating that the CNR value changes by changing the value of the control signal. Three characteristic curves are shown. When there is no object close to the receiving device, the characteristic curve 1701 is shown. The best CNR is obtained when the control signal value Vctrl is set to Vch. A characteristic curve 1702 indicates that there is an object close to the terminal and the influence thereof is large. At this time, the value of the control signal having the maximum CNR value is not Vch but Vbest. CNR3 measured in step S1603 of the flowchart shown in FIG. 16 is a CNR value on the characteristic curve 1702 when the control signal value is Vbest. A characteristic curve 1703 indicates that there is an object close to the terminal, but the effect is not as great as that of the characteristic curve 1502. At this time, the value of the control signal at which the CNR value is the maximum value is Vbest2. The CNR4 measured in step S1606 of the flowchart shown in FIG. 16 is a CNR value on the characteristic curve 1703 when the control signal value is Vbest.

  When the influence of an object close to the receiving apparatus changes from the state of the characteristic curve 1702 in FIG. 17 to the state of the characteristic curve 1703, the CNR value when the control signal value is set to Vbest changes from CNR3 to CNR4. ing. When this difference is equal to or less than the above-described threshold CNRth, the change in the characteristic curve is assumed to be small. In the flowchart of FIG. 16, the determination result in step S1607 is No, and the search for the optimal value of the control signal value is not performed. When this difference is equal to or greater than CRNRth, it is determined that there is a significant change in the characteristic curve. In the flowchart of FIG. 16, the determination result in step S1607 is Yes. Next, the process proceeds to step S1608, and an optimum value of the control signal value is searched again. In the example of FIG. 17, Vbest2 is searched for as the optimal value of the control signal value as a result of the re-search.

  Regarding operations other than those described here, the same operations as those in the first embodiment are performed. As described above, by operating according to the flowchart shown in FIG. 16, a change in CNR is measured at any time in a normal television viewing state, and the control signal value is re-searched when a change greater than the threshold CNRth occurs. To be implemented. As a result, even when the television viewing state of the receiving terminal is different from the state immediately after the start of the television function, it has been found that the state of the terminal has changed, and the control signal optimization process has been carried out so that the optimal control signal is always obtained. The value is maintained. In this way, stable TV viewing is always realized.

  The cause of the change in the measured value of CNR is not the case where the influence of an object close to the antenna changes, but the reduction of the electric field strength at the reception point due to the influence of a building shadow, the reception power due to the influence of the antenna directivity, etc. It is also possible that there is a decline. In this case, the characteristic curve 1702 in FIG. 17 moves in parallel in the direction in which the CNR value decreases. In step S1606 of the flowchart of FIG. 16, in this case as well, a value lower than CNR3 is read as CNR4, and the search for the control signal value is performed again. However, since Vbest is set as the optimum value of the control signal value as a result of the re-search, it is possible to obtain optimum reception conditions in this case as well.

  FIG. 18 is a flowchart for explaining a third embodiment of the receiving apparatus according to the present invention. An operation in which the operation according to the flowchart shown in FIG. 18 is adapted to the configuration of the block diagram shown in FIG. 10 will be described below.

  In FIG. 18, step S1801 is a state in which the operation of the television viewing function is started, and this receiving apparatus is activated. In the activated state of the receiving apparatus, initialization setting and channel selection setting are performed for the receiving circuit 103 in FIG. 10, and when a broadcast signal is input to the receiving circuit 103, the television can be viewed. The value of the control signal output from the arithmetic unit 901 to the tuning frequency adjusting unit 102 is treated as no object close to the receiving apparatus in the initial state, and is set to the Vch control signal value shown in FIG. Here, the control signal value Vch is a value associated with an arbitrary reception frequency fch by the graph of FIG. 3, and as fch, the frequency channel input by the user after the TV function is activated, and the reception device is operating last. The frequency corresponding to the frequency channel selected at that time or the frequency channel set in advance as the initial value of the receiving terminal is set.

  However, since there may actually be an object (such as the user) that is close to the receiving apparatus, an optimal control signal value is searched in step S1802. As a result of the search in S1802, Vbest is obtained as the optimum value of the control signal as described with reference to FIG. 8 (one set value among the three set values for the value of the control signal). In response to this result, the calculation unit 901 sets the value of the control signal output to the tuning frequency adjusting unit 102 to Vbest, and matches the tuning frequency of the antenna 101 with the signal frequency that the user desires to view. In step S1803, the reception circuit 103 measures the CNR in this state, and the calculation unit 901 reads the CNR value and records it as CNR5 in the storage unit 902. Thereafter, a normal viewing state is set as step S1804. Step S1805 is an end determination, and when the TV viewing function is turned off, this flowchart ends. If not turned off, the process proceeds to step S1806.

  In step S1806, the calculation unit 901 sets the control signal value to a value smaller than Vbest by a certain amount (Vbest-α), the CNR value at this time is measured by the reception circuit 103, and the calculation unit 901 reads the CNR value. Record as CNR6 in the storage unit 902. In step S1807, the calculation unit 901 sets the control signal value to a value (Vbest + α) that is a certain amount larger than Vbest, the reception circuit 103 measures the CNR value at this time, and the calculation unit 901 reads the CNR value. Recorded as CNR 7 in the storage unit 902. The CNR values in the three control signal values arranged at equal intervals are obtained by the processing of S1803, S1806, and S1807. The control signal values (Vbest−α) and (Vbest + α) are the other two setting values among the three setting values for the value of the control signal.

  In step S1808, it is determined by using these three CNR values whether an object close to the terminal has changed. Although details of the operation in S1808 will be described later, when it is detected that there is a change in an adjacent object, it is necessary to optimize the value of the control signal output from the calculation unit 901 to the tuning frequency adjustment unit 102. Determination is made, and the process proceeds to step S1809 to search for the optimum value. As a result of the search in S1807, a new optimum value Vbest2 is obtained as the value of the control signal. Upon receiving this result, the calculation unit 901 sets the value of the control signal output to the tuning frequency adjustment unit 102 to Vbest2 and sets the value of the antenna 101. The tuning frequency is matched with the signal frequency that the user desires to view, and the value of CNR5 is newly updated in step 1810, and the normal viewing state is set in step S1804.

If it is not detected in step S1808 that there is a change in an adjacent object, the search is not performed and the process returns to S1804 and the normal viewing state is continued.
Although not shown in FIG. 18, a process for returning the set value of Vctrl to Vbest after acquiring CNR7 is necessary after S1807 or after the determination process of S1808.
By repeating the steps from S1804 to S1808, even if a change occurs in an object close to the terminal and it is necessary to change the tuning frequency of the antenna 101, a change in state is detected in step S1808, and a new control is performed in S1809. Since the signal value Vbest2 is searched, a stable television viewing state is always maintained.

  Hereinafter, the determination method of S1808 will be described. The calculation unit 901 compares the values of CNR5, CNR6, and CNR7 recorded in the storage unit 902. If CNR5, which is the CNR value when the control signal value is Vbest, is the best among these three values, it is determined that there is no change in the object close to the antenna. At this time, the result of the re-search start determination in S1808 is No. When one or both of CNR6 and CNR7 are superior to CNR5, it is determined that there is a change in an object close to the antenna and a change has occurred in the tuning frequency of the antenna. At this time, the result of the re-search start determination in S1808 is Yes.

The features of this embodiment will be described in more detail.
FIG. 19A shows a characteristic diagram when CNR6 is superior to CNR5 and CNR7 is inferior in the determination in S1808. At this time, it is considered that the control signal value Vbest2 at which the maximum CNR value is obtained is at a position lower than Vbest. Therefore, in the process of searching for the optimum value of the control signal value performed in S1809, the minimum value of the search range can be set to Vch and the maximum value of the search range can be set to Vbest-α as the search range. As a result, the search range can be narrowed compared to the search range described with reference to FIG. 8, and the time required for the search can be shortened.

  Further, FIG. 19B shows a characteristic diagram when CNR7 is superior to CNR5 and CNR6 is inferior in the determination in S1808. At this time, it is considered that the control signal value Vbest2 at which the maximum CNR value is obtained is at a position higher than Vbest. Therefore, in the process for searching for the optimum value of the control signal value performed in S1809, the search range is set to the minimum value of the search range Vbest + α, and the maximum value of the search range is set to the control signal value corresponding to Vch + 100 MHz according to FIG. be able to. As a result, the search range can be narrowed compared to the search range described with reference to FIG. 8, and the time required for the search can be shortened.

  While the search is being performed, changing the control signal value changes the tuning frequency of the antenna and changes the signal power of the received signal. By shortening the time, it is possible to shorten the time during which the reception characteristics deteriorate, which is effective for the user to realize stable television viewing.

  As described above, by operating according to the flowchart shown in FIG. 18, a change in CNR is measured at any time in a normal television viewing state, and the control signal is detected when the change in the CNR characteristic with respect to the control signal value is detected. A value re-search is performed. As a result, even when the television viewing state of the receiving terminal is different from the state immediately after the start of the television function, it has been found that the state of the terminal has changed, and the control signal optimization process has been carried out so that the optimal control signal is always obtained. The value is maintained. In this way, stable TV viewing is always realized.

  Note that if the amount of change in the CNR value is small with respect to the change in the control signal value, there is a possibility that an erroneous determination occurs in the magnitude comparison of CNR5, CNR6, and CNR7. However, as already described in the CNR measurement method of FIG. 13, it is possible to obtain a highly accurate CNR value by reducing the measurement error of CNR measurement. In addition, by appropriately setting the value of Vbest-α, which is the value of Vctrl set to measure CNR6 and CNR7, and the value of α in Vbest + α, there is a possibility that erroneous determination occurs in the size comparison of CNR5, CNR6, and CNR7. It is possible to reduce. That is, by increasing the value of α, it is possible to increase the amount of change in the values of CNR6 and CNR7 with respect to CNR5, and to reduce erroneous determination due to measurement errors. Specifically, when the possible range of Vctrl is 0 V to 3.0 V, the value of α may be set to 0.1 V or 0.5 V, for example. Further, it is not necessary to set the same value on the upper side and the lower side for the value of α when calculating CNR6 and CNR7, Vbest−α when determining CNR6, and Vbest + β (where α ≠ β) when determining CNR7. Good. When the relationship between the antenna control signal value and the CNR shown in FIG. 4 is known in advance, it is possible to reduce erroneous determination due to measurement errors by increasing the value of α or β on the side where the inclination is gentle.

  As another example of the determination condition of S905 in FIG. 9, there is a method of detecting the occurrence of a change in the position, orientation, and operation state of the receiving terminal with an acceleration sensor. An example of determination using an acceleration sensor will be described with reference to FIG. In FIG. 20, 903 is a third storage unit, and 904 is an acceleration sensor. It is conceivable that the influence of an object close to the antenna changes as the position of the receiving terminal changes. Similarly, it is conceivable that the influence of an object close to the antenna changes due to the change in the direction of the receiving terminal. Similarly, when the operating state of the receiving terminal changes from the stopped state to a state other than the stopped state, and when the reverse operating state changes, the influence of an object close to the antenna may change. By providing the acceleration sensor 904 in the receiving device, it is possible to detect changes in the position, orientation, and operating state of the receiving terminal, and record these detection results at a predetermined interval in the third storage unit 903 in the computing unit 901. When the detected amount of change exceeds a predetermined value by processing the recorded result by the calculation unit 901, the tuning frequency of the antenna is changed due to a change in the position of the receiving terminal, a change in direction, a change in operating state, etc. 9 is output, the determination condition of S905 in FIG. 9 outputs Yes, the optimal value of the control signal is searched, and a new optimal value can be set.

  Although the determination conditions by the acceleration sensor have been described here, a contact sensor may be used instead of the acceleration sensor. By providing a contact sensor in the receiving device, it is possible to detect whether there is an object in contact with the receiving terminal. In particular, it is possible to detect whether or not there is an influence of the human body, the output of the contact sensor is recorded in the third storage unit 903, and the calculation unit 901 detects that a change has occurred in the output of the contact sensor. As a result, it is detected that a change has occurred in the object close to the receiving terminal. As a result, the determination condition in S905 in FIG. 9 is output as Yes, the optimum value of the control signal is searched, and the new optimum value is set. It becomes possible to do.

  As another example, a state sensor may be used. By providing the receiving device with a state sensor that detects a change in the opening / closing state of the receiving terminal, the computing unit 901 can detect the opening / closing state of the receiving terminal. Since the change in the open / closed state of the receiving terminal causes a change in the control signal value that optimizes the tuning frequency of the antenna, the state sensor outputs the open / closed state of the receiving terminal to the calculation unit 901, thereby The calculation unit 901 determines the change in the open / close state, and as a result, the determination condition of S905 in FIG. 9 outputs Yes, and the optimal value of the control signal can be searched and set to a new optimal value.

  As shown in this embodiment, by using a sensor such as an acceleration sensor, the operation of the flowchart shown in FIG. 9 can be realized with a minimum configuration change. As a result, even when the TV viewing state of the receiving terminal differs from the state immediately after the start of the TV function due to a change in an object close to the antenna, it is detected that the terminal state has changed, and the control signal optimization process is performed. As a result, the optimum control signal value is always maintained. In this way, stable TV viewing is always realized.

DESCRIPTION OF SYMBOLS 101 ... Antenna 102 ... Tuning frequency adjustment part 103 ... Reception circuit 104 ... Calculation part 201 ... Capacitance element 202 ... Variable capacitance element 203 ... Resistance 901 ... Calculation part 902 ... Storage unit 903 ... Sensor 1001 ... Cover body 1002 ... Main body

Claims (14)

An antenna that receives a radio wave and outputs a received signal corresponding to the received radio wave;
A reception circuit having a function of measuring the reception state or signal quality of the reception signal, the reception signal from the antenna being input;
A calculation unit having a function of reading the reception state or the signal quality measured in the reception circuit, and a function of outputting a control signal;
A tuning frequency adjusting unit having a function of adjusting a tuning frequency, which is a frequency at which the control signal is input and the gain of the antenna is maximized;
The reception state or the signal quality changes depending on the value of the control signal, and becomes the best when the frequency of the received radio wave matches the tuning frequency,
The calculation unit determines a range in which the value of the control signal in which the reception state or the signal quality is best may exist as a search range, and the reception state or the signal quality is the best from the search range. In a receiving device including search means for searching for an optimal value of a control signal,
The receiving device according to claim 1, wherein the searching means performs a search again for the optimum value of the control signal in response to the reception state or the signal quality of the received radio wave being not the best. The receiving device according to claim 1,
The receiving device includes a search range limiting unit that determines the search range to be a range narrower than a range of all values that the control signal can take. The receiving apparatus according to claim 1 or 2,
The re-search by the searching means is performed when the function of the receiving device is started.
The receiving apparatus is implemented when the reception state or the signal quality of the received radio wave is not the best in the normal operation state. The receiving apparatus according to claim 3,
The calculation unit sets the value of the control signal to two different values, a first setting value and a second setting value, and measures the reception state or the signal quality at each value, A receiving apparatus that determines whether or not to perform the re-search by the search unit based on a comparison result. The receiving device according to claim 4,
The first set value is the optimum value of the control signal searched by the search means, and the second set value is the control signal when the tuning frequency of the antenna matches the reception frequency. Value of
The calculation unit is configured such that the reception state or the signal quality when the control signal is the second set value is better than the reception state or the signal quality when the control signal is the first set value. Compare whether or not
In response to the comparison result that the search means is good, the search means performs a search again for the optimum value of the control signal. The receiving device according to claim 5,
The calculation unit sets the value of the control signal to the value of the control signal when the tuning frequency of the antenna matches the reception frequency instead of the re-search by the search means. apparatus. The receiving apparatus according to claim 3,
The calculation unit measures the reception state or the signal quality corresponding to the optimum value when the searching unit searches for the optimum value of the control signal, and again measures after searching the optimum value of the control signal. Comparing whether the difference between the reception state or the signal quality corresponding to the optimum value exceeds a predetermined threshold,
The receiving device according to claim 1, wherein the search means performs a re-search of the optimum value of the control signal in response to the comparison result that the difference exceeds the predetermined threshold. The receiving apparatus according to claim 3,
The calculation unit sets the value of the control signal to three different values: a first setting value, a second setting value, and a third setting value, and sets the reception state or signal quality at each value. A receiving apparatus that measures and determines whether or not to perform the re-search by the search means based on the comparison results. The receiving device according to claim 8, wherein
The first set value is the optimum value of the control signal searched by the search means, the second set value is a value obtained by increasing the optimum value by a predetermined value, and a third setting The value is a value obtained by reducing the optimum value by a predetermined value,
The calculation unit is configured such that the reception state or the signal quality when the control signal is the first set value is intermediate between the reception state or the signal quality when the control signal is the second to third. Compare whether or not there is
In response to the comparison result that the search means is in the middle, the search means re-searches for the optimum value of the control signal. In the receiving device according to any one of claims 4 to 9,
The receiving apparatus according to claim 1, wherein the optimum value in the condition is updated to the optimum value of the control signal obtained by the search means performing the re-search. In the receiving device according to any one of claims 4 to 10,
In response to termination of the function of the receiving apparatus, the value of the control signal is returned to the value of the control signal when the tuning frequency of the antenna matches the receiving frequency. An antenna that receives a radio wave and outputs a received signal corresponding to the received radio wave;
A reception circuit having a function of measuring the reception state or signal quality of the reception signal, the reception signal from the antenna being input;
A calculation unit having a function of reading the reception state or the signal quality measured in the reception circuit, and a function of outputting a control signal;
A tuning frequency adjusting unit having a function of adjusting a tuning frequency, which is a frequency at which the control signal is input and the gain of the antenna is maximized;
The reception state or the signal quality changes depending on the value of the control signal, and becomes the best when the frequency of the received radio wave matches the tuning frequency,
The calculation unit determines a range in which the value of the control signal in which the reception state or the signal quality is best may exist as a search range, and the reception state or the signal quality is the best from the search range. In a receiving device including search means for searching for an optimal value of a control signal,
In response to the detection output of the acceleration sensor that is attached to the receiving device and detects a change in the position and orientation of the receiving device as a change in acceleration exceeding a predetermined value, A receiving apparatus that performs a re-search of the optimum value. An antenna that receives a radio wave and outputs a received signal corresponding to the received radio wave;
A reception circuit having a function of measuring the reception state or signal quality of the reception signal, the reception signal from the antenna being input;
A calculation unit having a function of reading the reception state or the signal quality measured in the reception circuit, and a function of outputting a control signal;
A tuning frequency adjusting unit having a function of adjusting a tuning frequency, which is a frequency at which the control signal is input and the gain of the antenna is maximized;
The reception state or the signal quality changes depending on the value of the control signal, and becomes the best when the frequency of the received radio wave matches the tuning frequency,
The calculation unit determines a range in which the value of the control signal in which the reception state or the signal quality is best may exist as a search range, and the reception state or the signal quality is the best from the search range. In a receiving device including search means for searching for an optimal value of a control signal,
The searching means is re-searched for the optimum value of the control signal in response to detection output of a contact sensor attached to the receiving device and detecting contact of an object with the receiving device exceeding a predetermined value. The receiving apparatus characterized by implementing. An antenna that receives a radio wave and outputs a received signal corresponding to the received radio wave;
A reception circuit having a function of measuring the reception state or signal quality of the reception signal, the reception signal from the antenna being input;
A calculation unit having a function of reading the reception state or the signal quality measured in the reception circuit, and a function of outputting a control signal;
A tuning frequency adjusting unit having a function of adjusting a tuning frequency, which is a frequency at which the control signal is input and the gain of the antenna is maximized;
The reception state or the signal quality changes depending on the value of the control signal, and becomes the best when the frequency of the received radio wave matches the tuning frequency,
The calculation unit determines a range in which the value of the control signal in which the reception state or the signal quality is best may exist as a search range, and the reception state or the signal quality is the best from the search range. In a receiving device including search means for searching for an optimal value of a control signal,
The search means performs a re-search of the optimum value of the control signal in response to a detection output of an operation sensor that detects an operation state such as opening / closing of the lid of the receiving device exceeding a predetermined value. A receiving apparatus.

Images