JP2001231060A - Wireless selective call receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless selective call receiver that can realize both the improvement of reception sensitivity and the extension of the battery service life. SOLUTION: The wireless selective call receiver consists of an antenna 10, a reception demodulation section 20, and a control section 30. The control section 30 includes a synchronizing signal detection section 31, a code error correction section 32, a diversity composite section 33, a diversity buffer 34, a decoding section 35, an address detection section 36, an intermittent reception control section 37, a timing maintenance section 38, and a message memory 39. An iDROM 40 is connected to the address detection section 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio selective call receiver, and more particularly to a radio selective call receiver for receiving data such as messages transmitted by radio through a plurality of mutually overlapping base stations.

[0002]

2. Description of the Related Art Such a radio selective calling receiver or related prior art is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-234523.
Publication, "Selective paging receiver", JP-A-8-19570
No. 9, "Mobile communication system", JP-A-1-129628.
No. 5,049,849, which discloses a "time diversity transmission / reception system", and International Publication WO95 / 24786, a "time diversity communication system".

In recent wireless selective call receivers, in addition to selective call (message transmission), a service for delivering the same message (broadcast) to a large number of receiving terminals, which is called information provision, is often provided. In this case, the wireless address used for individual transmission and the wireless address used for providing information belong to different groups. Therefore, the ratio of receiving terminals (multi-frame receiving terminals) that receive a plurality of frames is increasing. Reception of a plurality of frames reduces the effect of intermittent reception and shortens the life of a built-in battery.

On the other hand, the reception operation of time diversity for re-receiving the same data in order to supplement the radio sensitivity is also described.
Since the same data is transmitted and received a plurality of times, this is an undesirable operation in terms of battery life. For this reason, in the case where the reception sensitivity can be obtained well in the conventional receiver,
It is common practice to stop the operation of diversity reception to obtain the efficiency of intermittent reception. However, the condition for not performing the diversity reception operation is the same as that for the above-described multi-frame terminal. However, the communication quality required for each purpose, that is, individual call and information provision is slightly different. Therefore, the time diversity receiving operation is easily performed for a frame requiring high quality, and the time diversity receiving operation is not easily performed for a frame having a high priority of battery life. It is possible to achieve both a long life and communication quality.

[0005]

However, according to the above-mentioned conventional radio selective calling receiver, it is not possible to automatically determine whether or not to perform the time diversity receiving operation. There is a problem that it is difficult to make the length sufficiently long.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a radio selective calling receiver which can automatically and selectively switch the time diversity receiving operation and effectively utilize the timing at which the diversity receiving operation is not performed. That is.

[0007]

A radio selective call receiver according to the present invention receives and demodulates a radio signal modulated by a selective call signal, and controls the operation of the reception / demodulation unit. A control unit for judging and controlling call reception and storing a received message, wherein the control unit includes an intermittent operation control unit, and when its own radio address belongs to a plurality of frames, It is characterized in that a condition for performing the time diversity receiving operation is determined and at a timing when the time diversity receiving operation is not performed, it is determined whether or not a transmission wave in a new area can be received.

According to the preferred embodiment of the present invention, the condition for performing the time diversity operation for each frame is automatically determined from the numerical value range of the radio address assigned to itself, and a new condition is determined at the timing when the time diversity operation is stopped. It is characterized in that it is determined whether or not a transmission wave in the area can be received. The control unit includes a data type statistical unit, and automatically determines the condition of the time diversity operation based on the statistical result of the type of the message received for each frame. The data type statistics unit obtains statistics of the length of the received message for each frame, and automatically determines the conditions for performing the time diversity operation. When the synchronization signal detection unit of the control unit cannot correctly receive the synchronization signal, the above-described determination is not performed in the next diversity operation, and the time diversity operation is performed. In addition, the control unit includes a non-diversity operation counter, and stops the time diversity operation for a predetermined number of times for a frame in which the expected diversity effect is not obtained even if the time diversity operation is performed, and the base station in a new area. It is characterized by confirming whether a transmission wave can be received.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration and operation of a preferred embodiment of a radio selective call receiver according to the present invention will be described below in detail with reference to the accompanying drawings.

First, in the radio selective calling receiver according to the present invention, in order to extend battery life, radio addresses are divided into several groups and time slots obtained by time division (hereinafter, this time slot is referred to as a "frame"). A method of selectively calling a wireless address belonging to a corresponding group every time is adopted. The wireless selective call receiver (or receiving terminal) receives data of a frame assigned to a group to which its own wireless address belongs. In order to supplement wireless sensitivity characteristics, a method of transmitting the same data a plurality of times (hereinafter, referred to as "time diversity") is also widely used, especially in Japan. In addition, services such as multi-area services are being provided at a nationwide level in order to enable wireless selective calling in a wide area.

FIG. 1 is a block diagram showing the configuration of a first embodiment of a radio selective call receiver according to the present invention. This radio selective call receiver includes an antenna (antenna) 10, a receiving / demodulating unit 20, and a control unit 30. The control unit 30 includes a synchronization signal detection unit 31, a code error correction unit 32, a diversity combining unit 33, a diversity buffer 34, a decoding unit 35, and an address detection unit 3.
6, an intermittent reception control unit 37, a timing maintenance unit 38, and a message memory unit 39. The address detector 36 includes an iDROM (individual number code memory) 4
0 is connected.

The antenna 10 receives a signal transmitted by radio (radio wave). The reception / demodulation unit 20 includes the antenna 10
Selects the frequency of the received signal and performs reception and demodulation. The synchronization signal detector 31 detects a synchronization signal from the received signal.
The code error correction unit 32 corrects an error in the received signal. Diversity combining section 33 compares the corresponding information of the data received a plurality of times and selects highly reliable data. The diversity buffer 34 stores data for performing a diversity operation. The decoding unit 35 selects and analyzes error-corrected data or received / demodulated data.
The address detection unit 36 compares the received data with its own wireless address. The intermittent reception control unit 37 determines the timing of receiving data addressed to itself from the analyzed data,
It also controls the operation / stop of the reception / demodulation unit 20. The timing maintaining unit 38 measures the time while the receiving / demodulating unit 20 is stopped for performing the next reception. The message memory unit 39 stores the received message addressed to itself. The iDROM 40 accumulates individual information necessary for radio selective calling such as a radio address and a frequency to be received. Although not shown, in addition to the above-described components, a display unit (LC
D), a notification unit for notifying the receiver of the arrival of the message by sound or light, an interface for transferring the received data to a personal computer (PC), and the like are added.

Next, the operation of the radio selective call receiver according to the present invention shown in FIG. 1 will be described with reference to FIGS. FIG. 2 is a timing chart showing the intermittent reception operation of the radio selective call receiver. FIG. 3 is a flowchart showing the intermittent reception operation of the radio selective call receiver. FIG. 4 is an explanatory diagram of the operation based on the map of the condition Jx. Further, in the following description, the time diversity will be mainly described with respect to a reception operation when data is retransmitted once.

In the radio selective calling receiver according to the present invention, the data whose frequency has been selected and demodulated by the receiving / demodulating section 20 are input to the synchronization signal detecting section 31, the code error correcting section 32 and the decoding section 35. The decoding unit 35 performs data analysis according to the signal format to be decoded and the content of the received data while selecting the result of error correction by the code error correction unit 32 or the data directly input to itself as necessary. The code error correction unit 32 outputs not only the data (information bits) for which the code error has been corrected, but also error number information. The diversity buffer 34 accumulates the error correction result output from the code error correction unit 32, the number of errors, the data position, and the number of times of reception (the number of times of diversity) while adding them. If the received data is retransmitted data (second or later), the diversity combining unit 33 takes out the data from the diversity buffer 34 in accordance with the position of the data currently being received, selects data with a low degree of error, and decodes the data. And outputs data to the address detection unit 36. On the other hand, in the case of the first data reception, diversity combining section 33 performs error correction data and error number output from code error correction section 32 without performing these operations, by decoding section 35 and address detection section 36. Output directly to.

The diversity buffer 34 also stores only the code correction data output from the code error correction unit 32 and the number of errors. The decoding unit 35 analyzes the reception data and error information output from the diversity combining unit 33, outputs information (timing information and current reception status) necessary for the intermittent reception operation to the intermittent reception control unit 37, and detects an address. The address detection unit 36 is activated at the necessary timing. The address detection unit 36 performs an address detection operation under the control of the decoding unit 35, and upon detecting its own address, requests the intermittent reception control unit 37 to acquire information including a message. The address detection unit 36 reads the unique information of the receiver including its own address from the iDROM 40 as necessary, and outputs the information to the intermittent reception control unit 37 as appropriate. The intermittent reception control unit 37 determines the data reception status based on the analysis result of the decoding unit 35 and the determination result of the address detection unit 36, and controls the intermittent reception illustrated in FIG.

Next, a description will be given with reference to a timing chart of the intermittent reception operation in FIG. In FIG. 2, (a) shows transmission contents, (b) shows intermittent reception operation when reception sensitivity is good,
(C) shows the intermittent reception operation of the conventional receiver when the reception sensitivity is not good, and (d) shows the intermittent reception operation of the receiver according to the present invention when the reception sensitivity is not good. FIG.
2A, the configuration of one frame of data A1 is shown in an enlarged manner. Each of the frames A to H has first (first) transmission data and retransmission (second) transmission data. At this time, even if the same data is transmitted as the initial data and the retransmission data of each frame, the reception state is substantially the same, so that the effect of the time diversity is not large. Therefore, FIG.
As shown in the transmission content of (a), the timing at which the data of A1 is retransmitted is the timing of A1r after the next initial data transmission after the intermittent reception interval. Therefore, the first data and the retransmission data belonging to one frame include data separated by one intermittent cycle.

The reception condition is good, and the first data (A1, A2
Alternatively, if no code error occurs in C1 and C2), diversity reception has no effect. Therefore, the intermittent reception control unit 37 does not perform the reception operation at the transmission timing of the retransmission data. At this time, there is no need to search for a transmission wave in a new area. Therefore, at the time diversity retransmission timing, the apparatus waits in a state of low power consumption.

On the other hand, if the signal condition is poor and code errors occur frequently as a result of receiving the first data, the intermittent reception control unit 37 sets the transmission timing of the retransmission data (A1r for A1 and A1r for A2). A2r (not shown), C1
The receiving operation is also performed for C1r and C2r (not shown) for C2. A time diversity operation is performed by the diversity combining unit 33 and the diversity buffer 34 to maintain the quality of received data. Generally, in the radio selective calling receiver, the reception / demodulation unit 20 consumes a large amount of current during its operation as compared with other parts. for that reason,
Due to the increase in the time diversity reception operation time described above,
Average current consumption increases and battery life is shortened. The presence or absence of the effect is determined for each frame, and the above-described time diversity reception (A1r for A1, A2r for A2,
Instead of canceling C1r for C1 and C2r for C2, an operation to determine whether or not transmission waves in a new area can be captured (for C (C1r) in FIG. 2C, FIG.
By performing (D process in (d)), it is possible to detect a transmission wave in a new area without increasing current consumption.

Next, the operation will be described with reference to the flowchart of FIG. The intermittent reception control unit 37 includes the synchronization signal detection unit 3
1, the synchronization is determined to be established when the reception data matches the signal format of the reception at the reception frequency at which reception is to be started (step S).
1). Thereafter, the intermittent reception control unit 37 receives information such as a reception frame of the corresponding area from the address detection unit 36. Further, the decoding unit 35 determines its own reception frame position (timing) based on information such as time slots extracted from the data received (step S2). Also, the intermittent reception control unit 37 simultaneously operates the address detection unit 36.
Information received from the receiver and the above-described step S
An operation condition map J0-Jn for time diversity reception is generated for each received frame determined in step 2 (step S3).

Thereafter, the reception parameters are initialized,
The data receiving operation is started (step S4). The intermittent reception control unit 37 first determines the timing at which the first data is transmitted (A1, A2, and C of the intermittent reception timing in FIG. 2).
1, C2), the receiving / demodulating unit 20 is operated to receive the transmitted first data (first time) (step S2).
5). Next, the result of code correction of the received data is compared with the time diversity reception operation condition of the frame (step S6). If the operation condition Zx is satisfied (step S6: Yes), the reception flag of the retransmission data of the current reception data is set (Rx2) (step S7). If the operation condition Zx is not satisfied (step S6: No), the above-mentioned flag is cleared (step S8).

Subsequently, since it is the retransmission timing of the previous transmission data for the same frame, the previously set time diversity operation control flag (Rx1) is referred to (step S9). If the flag is set (step S9: Yes), the previous retransmission data is received, the time diversity combining is performed by the diversity combining unit 33 (step S10), and Rx1 = Rx2 is set (step S11). The process returns to S5. If the flag is not set (step S9: No), the iDROM 4 determines whether there is a transmission wave (base station transmission wave) in an area overlapping the area where synchronization is currently established.
The determination is made with reference to the contents of 0 (step S12). If there is no such base station (step S12: No),
The operation of the reception / demodulation unit 20 is stopped, power consumption is reduced (step S11), and the process returns to step S5.
When there is an overlapping base station transmission wave, that is, when the transmission wave is registered in the iDROM 40 (step S1).
2: Yes) includes the reception / demodulation unit 20 and the decoding unit 35
To determine whether a new signal format from the overlapping base station can be detected (step S1).
3). In the signal format of the radio selective call receiver used in multi-area, the synchronization of base stations belonging to each area is generally guaranteed with high accuracy, so it is possible to receive even if reception of a new frequency is continued from the middle of the frame It is possible to determine whether or not it is possible. After the retransmission data reception processing is completed, including not performing reception / synchronization determination of a new reception wave, the diversity reception operation control flag is shifted to prepare for the next reception. When it is detected that a new transmission wave can be received, the number of code errors and the like are continuously counted, and when the error of the new transmission wave is low, the synchronization establishment area (base station = transmission wave) is switched. Is performed (step S14). In the determination of steps S12 to S14,
If the determination is No, the process proceeds to step S11.

A feature of the present invention is that the above-described time diversity operation is optimized for each frame (A sequence / C sequence) using an operation condition map for time diversity reception for each frame shown in FIG. The present invention is to perform diversity reception for the set time and to confirm a newly captured reception wave. In addition, since the area 1 and the area 2 in FIG. 4 have places overlapping each other, the state transits to a state in which it is determined in step S12 in FIG. 3 whether a transmission wave in a new area can be received. For example, when the synchronization establishment area is the area 1, the area overlaps with the area 2. Therefore, it is confirmed whether or not the transmission wave in the area 2 can be captured at a frame position (D position in FIG. 2D) where the reception sensitivity is deteriorated and the effect of time diversity cannot be expected. Conversely, if synchronization has been established in area 2, it is confirmed whether or not the transmission wave in area 1 can be captured. In the case of area 3, since it is known in advance that there is no overlapping area,
The confirmation operation of the new transmission wave (operation D in FIG. 2D) is not performed, and the power consumption is reduced.

[0023]

Next, another embodiment of the radio selective call receiver according to the present invention will be described. FIG.
It is a block diagram showing the composition of the 2nd example of a radio selective calling receiver by the present invention. FIG. 6 is a flowchart showing the operation of the radio selective call receiver of FIG. FIG. 7 shows an operation condition map of the time diversity reception in the radio selective call receiver of the second embodiment shown in FIG. In the block diagram of the second embodiment shown in FIG. 5, for the sake of convenience, the same or similar reference numerals are used for components corresponding to the components of the first embodiment of FIG. As apparent from FIGS. 1 and 5, the radio selective call receiver according to the second embodiment also includes an antenna 10, a reception / demodulation unit 20, a control unit 30 ', and an iD.
It is composed of a ROM 40. The configuration difference from the first embodiment is that a data type statistic unit 50 is added to the control unit 30 '. This data type statistics unit 50
Output signals of the decoding unit 35 and the address detection unit 36 are input. FIG. 7A shows a comparison between a wireless address and an assigned (received) frame, and FIG. 7B shows a statistical result by the data type statistical unit 50 and an operation condition map for diversity reception.

Next, a description will be given with reference to the flowchart of FIG. This flowchart includes steps T1 to T17
However, Steps T1 to T14 correspond to Steps S1 to S14 in FIG. 3, and thus the repeated description will be omitted, and Steps T15 to T17 will be described below. Step T1
After step 1, it is determined whether there is a message addressed to itself in the received data (step T15). When a message addressed to itself is received (step T15: Yes), statistical processing of the type of the received message is performed for each received wireless address (step T16). The operation result of the time diversity reception of the frame to which the wireless address belongs is reviewed as needed with reference to the statistical result of the data type statistic unit 50 and the operation result of the time diversity reception in FIG. 7B (step T17). In recent wireless selective call receivers, the message type information is included in the header of the message, so that the message type can be determined relatively easily. Furthermore,
Since the average message length is naturally determined by the type,
According to the method of this embodiment, it is possible to maintain the reception quality and reduce the average current consumption by relatively simple means.

In the second embodiment described above,
The method of determining the representative value of the length of the message transmitted for each frame from the statistical result of the message type has been described. However, FIG. 8 shows a map for directly calculating the average value of the message length for each wireless address statistically and determining the operation condition of the time diversity reception for each frame. FIG. 8A shows a comparison between the wireless address and the assigned frame, and FIG. 8B shows a statistical result and an operation condition map for time diversity reception. That is, classification is made according to whether the average message length is 20 characters or less or 20 characters or more.

Next, a description will be given of a third embodiment of the radio selective call receiver according to the present invention. FIG. 9 shows a block diagram of a third embodiment of the radio selective call receiver according to the present invention. FIG. 10 is a flowchart showing the operation of the radio selective call receiver according to the third embodiment. Even in the third embodiment, the antenna 10, the reception / demodulation unit 20,
It comprises a control unit 30 ″ and an iDROM 40.
The difference from the first embodiment in the configuration is that a non-diversity operation counter 60 connected to the intermittent reception control unit 37 is added.

In the flowchart of FIG. 10, a description will be given focusing on a portion related to the non-diversity operation counter 60, which is different from the flowchart of FIG. In the third embodiment, when a condition for performing time diversity reception (second reception) in a certain frame is satisfied, the non-diversity operation counter 6 of the corresponding frame is set.
Reference is made to a value Cx of 0 (step U10). This value Cx
Is not 0 (Step U10: Yes), Cx is decremented (Step U17). After that, at the time diversity reception timing of the corresponding frame,
It is confirmed whether or not the transmission wave of the base station overlapping the current synchronization establishment area can be received (step U18). Then, the reception state (the number of errors) is compared with the current synchronization area (step U19). Non-diversity operation counter 60
In the set of values Cx, time diversity reception of the corresponding frame is performed (step U11), and in step U12, when the result of the diversity combining is equal to or less than the specified value (exceeds the allowable number of errors) and the area over which synchronization is currently established is If there is a base station to be wrapped, a predetermined number N is set (step U14). When there is no overlapping base station in the area where synchronization is established, or when the combining effect of time diversity is obtained (when combining within the allowable error range), the counter value Cx is set to 0 ( By performing step U13), the operation of checking the transmission wave of the new base station is not performed, so that the reception capability equivalent to that of the related art can be maintained.

The configuration and operation of various preferred embodiments of the radio selective call receiver according to the present invention have been described above in detail. However, it is to be understood that these example embodiments are merely illustrative of the present invention. It will be readily apparent to those skilled in the art that various modifications can be made without departing from the spirit of the invention.

[0029]

As is apparent from the above description, according to the radio selective calling receiver of the present invention, various remarkable practical effects can be obtained as follows. By performing the time diversity reception, it is possible to reliably receive the message even when the state of the radio wave is poor. Checking the presence or absence of a base station that can be newly acquired during synchronization establishment is an effective means of preventing a message from being missed. However, when both are co-located, the state of radio waves deteriorates. In such a case, the time for receiving becomes longer, so that the life of the battery is shortened in exchange for the receiving sensitivity. This hinders the longevity of the battery (reduction in average current consumption) due to intermittent reception, which is a feature of the radio selective calling receiver. However, in the present invention,
Time diversity is performed in accordance with the required reception quality, and the reception time is used for capturing a new base station, so that both reception sensitivity and battery life can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of a radio selective call receiver according to the present invention.

FIG. 2 is a timing chart of an intermittent reception operation of the radio selective calling receiver shown in FIG. 1;

FIG. 3 is a flowchart showing an overall operation of the radio selective call receiver shown in FIG. 1;

FIG. 4 shows a condition Jx of the radio selective call receiver shown in FIG.
It is operation | movement explanatory drawing based on the map of FIG.

FIG. 5 is a block diagram showing a configuration of a second embodiment of the radio selective call receiver according to the present invention.

FIG. 6 is a flowchart showing an intermittent reception operation of the radio selective call receiver shown in FIG. 5;

FIG. 7 is an operation explanatory diagram of the radio selective call receiver shown in FIG. 5;

FIG. 8 is an explanatory diagram of an operation of receiving the radio selective call reception shown in FIG. 5;

FIG. 9 is a block diagram showing the configuration of a third embodiment of the radio selective call receiver according to the present invention.

FIG. 10 is a flowchart showing an intermittent reception operation of the radio selective call receiver shown in FIG. 9;

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 antenna 20 reception / demodulation unit 30, 30 ′, 30 ″ control unit 31 synchronization signal detection unit 32 code error correction unit 33 diversity combining unit 34 diversity buffer 35 decoding unit 36 address detection unit 37 intermittent reception control unit 38 timing maintenance unit 39 Message memory unit 40 iDROM 50 Data type statistical unit 60 Non-diversity operation counter

Claims (7)

[Claims] 1. A receiving / demodulating unit for receiving and demodulating a radio signal modulated by a selective calling signal, a control of an operation of the receiving / demodulating unit, a determination of call reception and a control of storing an incoming message. In the radio selective call receiver comprising a unit, wherein the control unit comprises an intermittent operation control unit, when its own wireless address belongs to a plurality of frames, determines the conditions for performing the time diversity reception operation for each frame and said A radio selective call receiver characterized in that it determines whether or not a transmission wave in a new area can be received at a timing when a time diversity reception operation is not performed. 2. A condition for performing a time diversity operation of each frame is automatically determined from a numerical range of a radio address assigned to itself, and a transmission wave in a new area can be received at a timing when the time diversity operation is stopped. The radio selective call receiver according to claim 1, wherein a determination is made as to whether or not the call is received. 3. The control unit includes a data type statistical unit,
Automatically determining the condition of the time diversity operation based on the statistical result of the type of the message received for each frame, and determining whether a transmission wave in a new area can be received at the timing when the time diversity operation is stopped. The radio selective call receiver according to claim 1, wherein: 4. The data type statistics section of the control section obtains statistics of the length of a message received for each frame,
The radio selective call reception according to claim 3, wherein a condition for performing the time diversity operation is automatically determined, and it is determined whether or not a transmission wave in a new area can be received at a timing when the time diversity operation is stopped. Machine. 5. A time diversity operation is performed in the next time diversity operation when the synchronization signal detection unit of the control unit cannot correctly receive a synchronization signal. 2. The radio selective call receiver according to 1. 6. The control unit includes a non-diversity operation counter, and stops the time diversity operation by a predetermined number of times for a frame for which a predetermined diversity effect is not obtained even when the time diversity operation is performed; 2. The radio selective call receiver according to claim 1, wherein an operation of confirming whether a transmission wave of a base station in a new area is receivable is performed. 7. The radio selective call receiver according to claim 6, wherein a frame for performing said operation is executed in a selected specific frame.