JP4507572B2 - Wireless communication device - Google Patents

Description

  The present invention relates to a wireless communication apparatus that performs communication using a wireless signal and a control data search method in the wireless communication apparatus.

  In recent years, development of wireless communication devices using the ISM band has been promoted, and TDMA communication using a frequency hopping method in which communication is performed while changing the communication frequency for each frame as one of communication methods of wireless communication devices in this frequency band. Wireless communication devices that perform the above have been developed.

  The standby operation of a base station and a terminal configured by a wireless communication apparatus that performs TDMA communication using these frequency hopping schemes is a TDMA communication that does not use a conventional frequency hopping scheme such as a PHS base station and terminal. Control signals (control data) are periodically transmitted from the base station side in a specific slot, as is the case with base stations and terminals configured with wireless communication devices to be performed, and base stations transmit standby terminals. It operates to receive a control slot and wait for a call from the base station. In a base station and a terminal configured by wireless communication devices that perform TDMA communication using a frequency hopping method, the transmission frequency of a control slot transmitted from the base station is changed as needed according to a predetermined hopping pattern. On the terminal side, the control frequency transmitted from the base station is received while changing the reception frequency according to the hopping pattern of the base station. In PHS, a base station transmits control data at a cycle of 100 msec, and a terminal in a standby state transmits control data corresponding to an incoming call group determined by the telephone number of the terminal among control data transmitted by the base station. It receives and waits for a call from the base station (see, for example, (Non-Patent Document 1)). In the PHS terminal, when a transition is made from a call state to a standby state for receiving control data, or when reception of control data for a new base station is started due to deterioration of the reception state of control data being standby, the reception frequency When the base station control data is continuously received in accordance with the fixed transmission frequency of the base station control data and the base station control data is captured, the operation shifts to the intermittent reception operation according to the control data transmission cycle, and enters the standby state. Transition. In a mobile wireless communication device such as a PHS terminal that is almost battery-powered, in order to prevent battery consumption, if the control data of the base station cannot be received by continuous reception for a certain period of time, reception is stopped to some extent. After the time elapses, continuous search is performed again, and the search for the base station control data is continued while repeating the operation of trying to receive the base station control data. In this way, when the terminal is in an environment where the base station cannot be captured and operates to repeat continuous reception and reception suspension for base station search, the reception time is shortened and the suspension time is lengthened from the viewpoint of current consumption. On the other hand, if the pause period is long, even if the terminal returns to the place where it can receive the control data of the base station, until the continuous reception for the next base station search is activated Because it is out of service area, the downtime cannot be made too long. In order to solve this problem, immediately after the start of acquisition of the base station, the pause time when the base station cannot be acquired by continuous reception is shortened, and continuous reception and reception pause are repeated. A search method has been proposed in which the control is performed so as to lengthen the period of time or the reception pause time is gradually increased when continuous reception and reception pause are repeated (see, for example, (Patent Document 1)). ).

Furthermore, in the frequency hopping wireless communication apparatus, the transmission frequency of the control data transmitted by the base station is not a fixed frequency, and the terminal controls the terminal when capturing the control data transmitted by the base station. Since it is necessary to sequentially receive a plurality of frequencies used for data transmission, the reception time for searching for a base station becomes longer than that of a TDMA wireless communication apparatus that does not perform frequency hopping, and current consumption Has been increasing. As a method of reducing the current consumption when searching for a base station, there are about three fixed types without searching all frequencies among a plurality of frequencies used by the base station for transmitting control data when searching for a base station. If the selected frequency is selected and only the selected frequency is searched and reception is not possible, the search for the base station is stopped, and after a certain period of time, the previously searched frequency is searched again. A method of repeating search and interruption by frequency was taken. In the ISM band, a wireless LAN using a frequency spreading method is used, and a wireless communication device using a frequency hopping method considers communication errors due to the wireless interference and determines the frequency of the base station search. In the selection, the base station is searched by selecting three frequencies, ie, a small part, a central part and a large part of the frequency band.
JP 2000-69552 A Second Generation Cordless Telephone System Standard 4.0th Edition Chapter 4 (Representative Figure Page 70 Figure 4.2.4)

  As described above, in the conventional wireless communication device, in the environment where the base station cannot be received, the base station search is repeated, and when the reception and the pause for the base station search are repeated in order to prevent an increase in current consumption, Since the period was lengthened from the middle or sequentially increased, if the base station was not able to receive for a long time, the next base station search could not be performed even if the base station moved to an environment where it could receive. There was a problem that the start-up is delayed and the return to the standby state may be delayed.

  Also, in a TDMA wireless communication apparatus using frequency hopping, base station search is performed at a plurality of predetermined frequencies in consideration of interference with a wireless LAN or the like while suppressing current consumption when searching for a base station. However, in an environment where there are multiple wireless LANs, there is a possibility that all of the selected fixed frequencies may be subject to interference, making it difficult to search for a base station. It was. In addition, in order to reduce the risk of reception errors due to interference, if the number of received frequencies is increased, the current consumption will increase in situations where the base station cannot receive without interference due to interference. Had.

  In this wireless communication apparatus and control data search method, it is required to reduce the current consumption of the search operation in an environment where the control data from the base station cannot be searched.

The present invention aims to provide a radio communication equipment capable of reducing the current consumption of the search operation in the environment that can not be retrieved control data from the base station.

The wireless communication apparatus of the present invention communicates with a base station that transmits control data using a frequency hopping method in which transmission is performed while changing the transmission frequency in a predetermined order. A wireless communication device for receiving, having a wireless unit for receiving a radio signal and a control unit for controlling the whole, the control unit controls data for capturing control data transmitted by the base station The radio unit is controlled to receive one of the frequencies used for transmission, and if the control data cannot be received, the radio unit can be stopped to receive the control data. Without repeating the reception and stop of the radio unit, the number of frequencies to be selected for each search is reduced until the predetermined number of searches , and the frequency types to be selected for each search are reduced and received. Times After, and a configuration for performing control so as to receive by changing the type of the frequency to select the number of frequencies selected for each search is constant, and for each search.

  As a result, a wireless communication apparatus capable of reducing the current consumption of the search operation in an environment where the control data from the base station cannot be searched is obtained.

Further, it is possible to shorten the time which the current at the time of reception for the base station search is consumed in an environment unable to receive group Chikyoku, is possible to reduce the current consumed while not receiving the base station The advantageous effect that it can be obtained.

In addition, after a predetermined number of searches, the base station can be searched efficiently at a plurality of frequencies while suppressing current consumption by controlling the number of selected frequencies to be constant and changing the selected frequency. Can do.

The purpose of the present invention is to reduce the current consumption of the search operation in an environment where the control data from the base station cannot be searched, and to transmit the control data in order to capture the control data transmitted by the base station. The radio unit is controlled to receive one of the frequencies used for the control, and when the control data cannot be received, the radio unit is controlled to stop receiving, and the control data cannot be captured. When repeating the reception and stop of the radio unit, the number of frequencies to be selected for each search is reduced until the predetermined number of searches , and the frequency types to be selected for each search are reduced and received. after was achieved by performing a control to receive by changing the type of the frequency to select the number of frequencies selected for each search is constant, and for each search.

(Embodiment 1)
FIG. 1 is a block diagram showing a wireless communication apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a TDMA frame and slot used in communication between the wireless communication apparatus of FIG. 1 and a base station, and frequency hopping. FIG. 3A is a timing diagram illustrating the transmission timing of control data from the base station, FIG. 3B is a timing diagram illustrating the reception timing in the wireless communication apparatus, and FIG. 4 is the wireless communication apparatus. FIG. 5 is a timing diagram showing an operation of searching for a base station control data transmission signal and repeating the search and stop without receiving the base station control data, and FIG. 5 shows the base station control data transmission signal. It is a flowchart which shows the operation | movement which repeats a search and a stop, without searching and receiving the control data of a base station.

  Also, (Table 1) shows the frequency and the order of use when communication is performed between the wireless communication apparatus and the base station by attaching an index.

  In FIG. 1, reference numeral 100 denotes an antenna that transmits and receives radio signals to and from a base station (not shown), and 101 denotes a radio unit that generates radio signals to be transmitted by modulating transmission data into radio signals and demodulates received radio signals. , 102 adds bit synchronization data, frame synchronization data, error detection code, etc. to the transmission data to generate a data string to be transmitted in one slot of TDMA, and extracts audio data and control data from the received signal to determine error And a frame processing unit 103 for digitally converting an analog audio signal to be transmitted, and an audio processing unit for converting received audio data into an analog audio signal, and a microphone for inputting and outputting the audio as an audio signal , 105 is a speaker for outputting a voice signal as voice, 106 is an operation unit for inputting a telephone number, and 107 is Display unit for displaying the input telephone number, date and time, call time, operating state of wireless communication device, remaining battery level, etc., 108 is a counting unit that counts the time of search time and stop time when searching for a base station, 109 is a first storage unit that stores the number of searches, 110 is a second storage unit that stores a hopping pattern for frequency hopping, and 111 is a frequency that is used next time for the hopping pattern that is stored in the second storage unit 110. A third storage unit 120 is a control unit that controls the entire apparatus. In the following description, an example is shown in which the wireless communication apparatus uses 10 types of frequencies f1 to f10, switches frequencies from f1, f3,... In order from f1, and controls frequency hopping. Then, as shown in Table 1, the second storage unit 110 stores the frequencies f1 to f10 and the corresponding index numbers, and the third storage unit 111 stores them in the second storage unit 110. An index number for designating a specified frequency is stored.

First, the operation of TDMA communication by frequency hopping will be described with reference to FIG. FIG. 2 shows TDMA frames and slots and frequency hopping states when communicating between the base station and the wireless communication apparatus of FIG. In the present embodiment, the time axis is divided into basic units called frames, one frame is divided into eight slots, the transmission slots of the base station are the previous four slots (slots 1 to 4) in the frame, the base station 4 shows a configuration of a TDMA frame and a slot that perform four-way multiplexing, with four reception slots (transmission slots of the wireless communication apparatus) as the last four slots (slots 5 to 8) in the frame. As an example of frequency hopping operation, FIG. 2 shows an example in which each slot in the same frame uses the same frequency and is operated so as to switch the frequency to be used when the frame changes.
That is, in the example of FIG. 2, slots 1 to 8 of frame 1 communicate at the frequency of f1, slots 1 to 8 of the next frame 2 communicate at the frequency of f2, and thereafter each time the frame changes in the same manner. In this example, f1 to f10 are used in a cycle of 10 frames by switching the frequencies used for f3, f4... F10. In addition, a base station of a wireless system that performs TDMA communication while performing frequency hopping transmits control data at regular intervals during operation, and a wireless communication device that waits for the base station transmits control data transmitted by the base station. Receive, establish frequency hopping and frame and slot synchronization and communicate with base station. In the present embodiment, the base station transmits control data in slot 1 of each frame (slots indicated by hatching in FIG. 2), and communication between the base station and the wireless communication apparatus is performed by four slots in the frame. In other words, an example will be described in which any combination of slot 1 and slot 5, slot 2 and slot 6, slot 3 and slot 7, and slot 4 and slot 8 is performed.

  Next, an example will be described in which the wireless communication apparatus in FIG. 1 operates in a wireless system that performs communication with the frequency hopping and TDMA frame and slot configurations shown in FIG.

  First, an outline of an operation in which a wireless communication apparatus synchronizes frequency hopping and TDMA frames and slots with a base station will be described. The details of the operation in which the wireless communication apparatus in a state where it cannot receive the base station repeats the operation for synchronizing the frequency hopping and the TDMA frame and slot with the base station will be described separately.

  The control unit 120 reads the frequency of the index number “1” in the second storage unit 110, that is, f1, and controls the wireless unit 101 and the frame processing unit 102 so as to continuously receive at the frequency of f1. A reception signal from the antenna 100 is demodulated by the radio unit 101 and output to the frame processing unit 102. The frame processing unit 102 detects the frame synchronization data from the demodulated signal. When the frame synchronization data is detected, the frame processing unit 102 separates the control data and the error detection code following the frame synchronization data, and receives them based on the separated error detection code. Control data error determination is performed, and if there is no error, the control data is notified to the control unit 120. The control unit 120 notified of the control data selects a base station based on the base station ID included in the control data. When shifting to the synchronization state with the received base station, the control unit 120 performs control so as to receive one slot at a period of one frame, and is stored in the third storage unit 111 for each reception. The wireless unit 101 is controlled to perform reception while sequentially switching the frequency read from the second storage unit 110. That is, when receiving the control data transmitted from the base station at the frequency of f1 during continuous reception, the control unit 120 writes the index = 2 indicating the next frequency in the third storage unit 111 and stops continuous reception. Thus, the wireless unit 101 and the frame processing unit 102 are controlled. Then, the control unit 120 controls the radio unit 101 and the frame processing unit 102 to start reception in accordance with the transmission timing of control data from the base station after one frame, and at this time, the third memory The index stored in the unit 111, that is, “2” is read, the corresponding frequency, that is, f2 is read from the second storage unit 110, the reception frequency is set, and stored in the third storage unit 111 for the next reception. The index is updated to “3”. Further, as described above, the control unit 120 continues to receive the control data of the base station, receives information on the transmission slot included in the control data, and determines the slot position of the control data from the base station. Know and establish slot synchronization. That is, when transmission of control data from the base station is performed in slot 1 of each frame as shown in FIG. 2, the base station periodically sets a transmission slot in the control data transmitted in the first slot. The wireless communication apparatus that transmits the data including the notification of “1” and receives the notification thereafter sets the timing of the frame and the slot so that the receiving slot of the control data from the base station becomes one slot. Set and establish frame and slot synchronization with the base station.

FIG. 3 is a timing diagram for explaining an operation in which the wireless communication device searches for a transmission signal of control data for the base station and shifts to a standby state. The wireless communication device described above performs control data for the base station. The operation to synchronize with the transmission slot is shown. As shown in FIG. 3, when the search operation is started, the wireless communication apparatus starts continuous reception at the frequency of f1. The base station transmits the control data while switching the frequencies in order of f1, f2,... F10. When the base station transmits at the frequency of f1, the base station control data is transmitted by the wireless communication apparatus. Control is started from continuous reception to intermittent reception in a frame period, and the reception frequency is sequentially switched from f2, f3,.

  Next, an operation during a call between the wireless communication apparatus and the base station will be described.

  The wireless communication apparatus shown in FIG. 1 can perform voice communication with other telephones and wireless communication apparatuses via a base station. When a telephone call is made from the wireless communication apparatus to another apparatus, the user operates the operation unit. The other party's telephone number and a call key for making a call request are input from 106 to make a call. When a transmission operation is performed by the operation unit 106, the control unit 120 sends control data for calling the base station to the frame processing unit 102. The frame processing unit 102 receives the control data from the control unit 120 in accordance with the reception timing of the base station. The bit synchronization data, frame synchronization data, error detection code, etc. are added to the control data for output to the wireless unit 101, and the data sequence output from the frame processing unit 102 is converted into a wireless signal by the wireless unit 101. And transmitted from the antenna 100. At this time, as described above, the control unit 120 establishes synchronization between the frequency hopping and the frame and the slot, and the control data for calling the base station becomes the slot for transmitting the control data for the base station. The transmission timing is controlled so that transmission is performed in the corresponding reception slot. That is, when the base station is transmitting control data in the first slot as shown in FIG. 2, the radio communication apparatus calls control data for calling the base station in the fifth slot at the same frequency as the reception frequency in the first slot. Send. Then, the control unit 120 controls the radio unit 101 and the frame processing unit 102 to wait for a response from the base station while switching the frequency for each frame, receives a response from the base station, and receives a response from the base station Thereafter, control data for call connection is exchanged. When the base station is notified that the other party has responded, the control unit 120 controls the frame processing unit 102 and the voice processing unit 103 so as to start a voice call. The received voice signal is transmitted to the voice processing unit 103. Audio converted from analog and output from the speaker 105 and input from the microphone 104 is converted into an audio signal. The audio signal is converted into a digital signal by the audio processing unit 103, processed by the frame processing unit 102, and then processed by the radio unit 101. It is converted into a radio signal and output, and a voice call is started.

  When a call is made to the wireless communication apparatus from another apparatus, the base station transmits control data for notifying the wireless communication apparatus of the incoming call and notifies the wireless communication apparatus of the incoming call. For this reason, the wireless communication device operates to receive control data for the base station in a state other than during a call. Then, when receiving the control data for notifying the incoming call, the wireless communication apparatus exchanges the control data for call control with the base station in the same manner as the above-described transmission operation, and the control unit 120 displays the incoming call on the display unit 107. Control is performed so as to display the notification, and when the user performs an incoming call response operation from the operation unit 106, control is performed so as to start a voice call.

  Next, the details of the operation when the wireless communication apparatus in a state where it cannot receive the base station repeats the operation for synchronizing the frequency hopping with the TDMA frame and slot with the base station will be described. .

  As described above, the wireless communication device receives control data transmitted from the base station at the start or end of the call, and synchronizes the frequency hopping with the frame and the slot with the base station. If the base station is unable to receive the data even though it shifts to the standby state, reception and stop for a certain time are repeated until the control data of the base station can be received.

That is, when the operation for synchronizing with the base station is started, first, the control unit 120 first sets the number of searches stored in the first storage unit 109 as the search start index in the third storage unit 111 in advance. The number of remainders divided by a determined value (hereinafter, an example in which this value is 5) is set as an index, and the frequency corresponding to the set index is read from the second storage unit 110 and received at the read frequency. The wireless unit 101 and the frame processing unit 102 are controlled so as to start, and the continuous reception time is set in the counting unit 108. When the base station control data cannot be received and the continuous reception time counted by the counting unit 108 has elapsed, the counting unit 108 notifies the control unit 120 that the count has expired. The control unit 120 notified of the expiration of the count reads the number of searches stored in the first storage unit 109, and the number of searches stored in the first storage unit is a predetermined number of times (hereinafter this number of times). If the number is less than or equal to the number of searches read from the first storage unit 109, the frequency index stored in the third storage unit 111 is updated by the number equal to the number of searches. If the stored number of searches exceeds a predetermined number, the frequency index stored in the third storage unit 111 is determined in advance (an example in which this value is 5 will be described below). Only update). Then, until the updated index exceeds the maximum value of the index (10 in the example of (Table 1)), the frequency corresponding to the updated index is read from the second storage unit 110 and received at the read frequency, as described above. The wireless unit 101 and the frame processing unit 102 are controlled so as to perform the reception, the continuous reception time is set in the counting unit 108, and reception is performed until the reception time counted by the counting unit 108 expires. The reception is performed while updating the index, that is, changing the frequency. When the updated index exceeds the maximum value of the index (10 in the example of (Table 1)), the control unit 120 controls the radio unit 101 and the frame processing unit 102 to be in a reception stopped state, and stores the first memory. The number of searches stored in the unit 109 is incremented, and the stop time is set in the counting unit 108. Then, when the stop time expires and the count unit 108 notifies the control unit 120 that the stop time has expired, the control unit 120 controls each unit in the same manner as the operation at the start of the search, as described above, and Resuming reception for control data search, and then repeating the search operation for the base station control data while repeating reception and reception stop while switching the frequency until the base station control data is received. When reception is completed, the number of searches in the first storage unit 109 is returned to “1”, and the above-described wireless communication apparatus synchronizes frequency hopping and TDMA frames and slots with the base station. The operation described in the overview of the operation is followed to shift to the synchronization state.

  Next, the switching of the reception frequency at the time of searching for a base station when the radio communication apparatus is composed of 10 types of frequencies of f1, f2,... F10 as shown in (Table 1) by the above control will be described. To do.

  When the search for the base station is started, first, in the first search, reception is started in order from the frequency f1 corresponding to the remainder of 1 index obtained by dividing the search count by 5, and the search count is 3 or less. The index is updated by one equal to the number of searches, and the reception frequency is switched to f1, f2,. After receiving f10, the value obtained by adding the number of searches = 1 stored in the first storage unit 109 to the index = 10 stored in the third storage unit 111 exceeds the maximum value of the index = 10. The number of searches in the first storage unit 109 is incremented to “2”, and reception is stopped for the time counted by the counting unit 108.

Then, after the stop time counted by the counting unit 108, the second search is started, and in the second search, reception is started in order from the frequency f2 corresponding to the remaining 2 index obtained by dividing the number of searches by 5. Since the number of searches is three or less, the index is updated by two equal to the number of searches, and the reception frequency is switched to f2, f4. After the reception of f10, the value obtained by adding the number of searches = 2 stored in the first storage unit 109 to the index = 10 stored in the third storage unit 111 exceeds the maximum value of the index = 10. The number of searches in the first storage unit 109 is incremented to “3”, and reception is stopped for the time counted by the counting unit 108.

  Similarly, the third search is started after the stop time counted by the counting unit 108. In the third search, reception is started in order from the frequency f3 corresponding to the remaining 3 indexes obtained by dividing the number of searches by 5. Since the number of searches is three or less, the index is updated by 3 equal to the number of searches, and the reception frequency is switched to f3, f6, and f9, and reception is performed for a fixed time. After receiving f9, the value obtained by adding the number of searches = 3 stored in the first storage unit 109 to the index = 9 stored in the third storage unit 111 exceeds the maximum value of the index = 10. The number of searches in the first storage unit 109 is incremented to “4”, and reception is stopped for the time counted by the counting unit 108.

  Then, the fourth search is started after the stop time counted by the counting unit 108, and in the fourth search, reception is started in order from the frequency f4 corresponding to the remaining 4 indexes obtained by dividing the number of searches by 5. Since the number of searches exceeds 3, the index is updated by 5 and the reception frequency is switched between f4 and f9, and reception is performed for a fixed time. After the reception of f9, the value obtained by adding 5 to the index = 9 stored in the third storage unit 111 exceeds the maximum value of the index = 10, so the number of searches in the first storage unit 109 is set to “5”. Increments to "" and stops reception for the time counted by the counting unit.

  Thereafter, similarly to the fourth search, f5 and f10 are repeated in the fifth search, and reception and reception stop at two frequencies are repeated while changing the frequencies to f1 and f6 in the sixth search.

  FIG. 4 shows the timing of the operation in which the wireless communication apparatus repeats continuous reception and reception stop while changing the frequency without receiving control data of the base station. In FIG. 4, the frequency is shown only by numbers, and f is omitted.

  As shown in FIG. 4, when the search operation is started in the wireless communication apparatus in a state where the control data of the base station cannot be received, continuous reception is performed for a certain time while switching the frequency from f1, f2,... F10. Then, the continuous reception is stopped. Then, the continuous reception is resumed, continuous reception is performed for a fixed time while switching the frequency between f2, f4... F10, and then the continuous reception is stopped. Similarly, continuous reception and reception stop are repeated while reducing the number of frequencies to be continuously received. In the final period, continuous reception and reception stop while switching two types of frequencies are repeated, Receive. Note that the continuous reception time at each frequency is controlled to be one or more periods of frequency switching of transmission of control data of the base station, that is, a time longer than T0 in FIG. It is determined that the base station transmits control data at the corresponding frequency at least once within the period of time and can be received by the wireless communication apparatus.

  Next, a search method (control data inspection / search method check) in which the wireless communication apparatus searches for a base station will be described with reference to FIG.

  The flowchart of FIG. 5 shows a control flow when the wireless communication device searches for the control channel of the base station when the power is turned on, after the call is finished, or when it is difficult to receive the control channel of the base station on standby. Show.

When the search for the control channel of the base station (that is, the search for control data) is started, first, the number of searches = 1 is set as the initial value setting (S1), and an index for determining the search frequency (Index and FIG. 5). Is calculated) (S2). The setting of the initial value of the number of searches in step S1 is not necessary if the search is already set for the next search at the end of the search. Also, “mod” in step S2 means the remainder of the division, and an example is shown in which the remainder obtained by dividing the number of searches by 5 is used as the index value. Subsequently, the reception frequency is set to the frequency indicated by the index, the timer for measuring the reception time is started, and the search start control, that is, the reception circuit is made ready to receive the control channel of the base station and is continuously received. Is performed (S3). After the search is started, it is determined whether or not the base station has been able to receive (S4) and whether or not the timer for monitoring the expiration of the reception time has expired (S5). When the base station is received during continuous reception, “Yes” is determined in step S4 to determine whether or not the base station has been received, the search is terminated, and the synchronization is continued with the transmission timing of the control channel of the base station. Transition to intermittent reception operation (not shown). If the state in which the control channel of the base station cannot be received continues, detection of the base station is continued until the timer expires. If the timer expires, a determination is made as to whether or not the timer has expired. ", And the process proceeds to step S6 for determining the number of searches. In step S6, if the number of searches is less than the specified number (here, 4), the process proceeds to step S7 where the index is updated by the number of searches. If the number of searches is equal to or greater than the specified number, the index is set to a predetermined value (here, +5). ) Proceed to step S8 for updating. After updating the index in step S7 or step S8, it is determined whether the index exceeds the maximum index value (here, 10) (S9). If the index does not exceed the maximum value, the next frequency is received. Therefore, the process returns to step S3. When the index exceeds the maximum value, the search is stopped, that is, the receiving circuit is turned off, the number of searches is incremented, and a timer is started to count the stop time (S10). Then, the determination of whether or not the timer has expired (S11) is repeated, and when the timer expires, the process proceeds to “Yes”, returns to step S2, and reception for search is started again.

  In the description of the present embodiment, when the wireless communication device repeats the search operation in an environment where the control data of the base station cannot be received, reception and stop are repeated while changing the reception frequency, and reception is performed up to a certain number of times. The example of reducing the number of frequencies and then fixing the number of frequencies to be received and repeating reception and stop while changing only the frequency has been shown. It is also possible to repeat the reception and the stop while changing only. It is also possible to repeat reception and stop while changing the reception frequency from the start of search, reduce the number of received frequencies up to a certain number of times, and then repeat reception and stop with the number of received frequencies and frequency fixed. This is possible and has an effect of simplifying the control for determining the reception frequency.

  Also, in this embodiment, when the wireless communication device repeats the search operation in an environment where the base station control data cannot be received, the reception and stop are repeated while changing the reception frequency, and the number of frequencies to be received up to a certain number of times. In this example, the number of frequencies to be received is fixed, and reception and stop are repeated while changing only the frequency. A fixed reception is performed, and after shifting to a certain number of times, it is possible to reduce the number of received frequencies and fix the reception, and there is an effect that the control for determining the reception frequency can be simplified.

  Furthermore, in the present embodiment, an example has been shown in which the continuous reception time of each frequency when repeating reception and stop is constant, but the continuous reception time of each frequency is lengthened at the start of the search and shortened in the middle. It is also possible to perform control as described above. In this case, since the start of reception takes a long time for continuous reception at the same frequency, if the base station control data cannot be received due to a temporary radio error, it is determined that reception is not possible at the corresponding frequency. Thus, the frequency of switching to the next frequency is reduced, and it is possible to reduce the waste of power consumed in the stable time of a transmission circuit such as a synthesizer for switching the reception frequency.

Furthermore, although an example in which the reception stop time when the reception and the stop are repeated is made constant in the present embodiment, the reception stop time can be variably controlled. When the reception and the stop are repeated, the current consumption can be further reduced by gradually increasing the stop time. Also,
Reducing the stop time by a further percentage while reducing the total time of each successive reception, so as to reduce the percentage of the stop time in the total time of each successive reception and the sum of the subsequent pause times per time As a result, it becomes possible to return to the synchronization state earlier when the reception is possible while reducing the current consumption.

  As described above, according to the present embodiment, it has radio section 101 that receives radio signals and control section 120 that controls the whole, and control section 120 captures control data transmitted by the base station. Therefore, the wireless unit is controlled to receive one of the frequencies used for transmitting the control data of the base station, and when the control data cannot be received, reception of the wireless unit 101 is stopped. By performing control to reduce the number of frequencies selected at the time of reception when the reception and stop of the wireless unit 101 are repeated without acquiring the control data transmitted by the base station, In the environment where the base station cannot be received, the time during which the current for receiving the base station is consumed can be shortened, so that the current consumed while the base station cannot be received can be reduced. Search and pause can be repeated without increasing the search pause time provided to reduce current consumption in an environment where the base station cannot be received, so reception is possible regardless of the duration during which reception is not possible. The delay in returning to the standby state can be reduced when a new state occurs, and if a temporary base station reception error or fixed frequency steady-state error occurs at the start of search, Since the control is performed so as to increase the number of frequencies to be searched, it can be determined that the base station has not been received, the search is stopped, and the delay in returning to the standby state can be reduced.

  In addition, the wireless unit 101 includes a wireless unit 101 that receives a wireless signal and a control unit 120 that controls the whole. The control unit 120 connects the wireless unit 101 to the base station in order to capture control data transmitted by the base station. Control is performed so that one of the frequencies used for transmission of control data is received. If the control data cannot be received, control is performed so that reception of the radio unit 101 is stopped, and the base station transmits Base station search in an environment where the base station cannot receive by controlling to change the frequency selected at the time of reception when the reception and stop of the wireless unit 101 are repeated without acquiring the control data to be performed For this reason, it is possible to shorten the time during which the current during reception is consumed, so that the current consumed while the base station cannot receive can be reduced and the base station cannot receive. Search and pause can be repeated without increasing the search pause time provided to reduce current consumption. The delay in returning to the state can be reduced, and when a part of the frequency used for transmission of control data cannot be received due to interference, the frequency to be searched for is repeated when searching and stopping. Since the control is performed to change, even if a reception error occurs at a part of the transmission frequency of the control data due to radio interference, the search is repeated only at the frequency where the reception error has occurred due to the interference and reception is impossible. It is possible to reduce the delay in returning to the standby state, and it is possible to suppress current consumption by the pause period.

The present invention can reduce the current consumption of the search operation in the wireless communication device and related to the wireless communication equipment, environment in which the search can not be the control data from the base station communicates by radio signals.

1 is a block diagram showing a wireless communication apparatus according to Embodiment 1 of the present invention. FIG. 1 is a timing diagram illustrating TDMA frames and slots and frequency hopping used in communication between the wireless communication apparatus of FIG. 1 and a base station. (A) Timing chart showing transmission timing of control data from base station, (b) Timing chart showing reception timing in radio communication apparatus Timing diagram showing an operation in which a wireless communication device searches for a transmission signal of control data of a base station and repeats searching and stopping without receiving control data of the base station The flowchart which shows the operation | movement which a wireless communication apparatus searches the transmission signal of the control data of a base station, and repeats a search and a stop, without receiving the control data of a base station

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Antenna 101 Radio | wireless part 102 Frame processing part 103 Audio | voice processing part 104 Microphone 105 Speaker 106 Operation part 107 Display part 108 Counting part 109 1st memory | storage part 110 2nd memory | storage part 111 3rd memory | storage part 120 Control part

Claims (4)

A wireless communication device that communicates with a base station that transmits control data using a frequency hopping method in which transmission is performed while changing the transmission frequency in a predetermined order, and that receives control data of the base station during standby. And
A radio unit that receives a radio signal, and a control unit that controls the whole,
The control unit controls the radio unit to receive one of the frequencies used for transmission of the control data in order to capture the control data transmitted by the base station, and Control to stop the reception of the radio unit if it could not be received,
When receiving and stopping the radio unit without capturing the control data, the number of frequencies to be selected for each search is reduced up to a predetermined number of searches , and the type of frequency to be selected for each search is selected. Reduce and receive
Given after the number of searches, a radio communication apparatus and controls such as a constant number of frequencies to be selected for each search, and receives by changing the kind of a frequency selected for each search. 2. The radio according to claim 1, wherein the control unit performs control so that reception is performed by reducing a frequency type selected for each search so as not to be adjacent on the frequency until a predetermined number of searches. Communication device. 3. The control unit according to claim 1, wherein after the predetermined number of searches, the control unit performs control so that the frequency type selected for each search is changed so as not to be adjacent on the frequency. The wireless communication device described. 4. The wireless communication apparatus according to claim 1, wherein the reception stop time when the reception and stop of the wireless unit are repeated is constant.

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