JP2002204181A - Mobile radio terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile radio terminal equipment capable of lengthening a continuously serving time by reducing a power consumption. SOLUTION: A controller 100 controls a searcher 16a since it is inferred that no fault occurs in a communication with a receiving base station for a while in a state in which a moving speed (v) is smaller than a Vth so that the mobile radio terminal equipment moves at a low speed because a radius (r) of a cell is larger than an Rth and a power level (p) is larger than a Pth so that the equipment is inferred to be locate near the receiving base station based on the level (p) of the receiving signal detected by a signal processing unit 17 from the base station used to communicate, the radius (r) of the cell formed by the base station and the moving speed (v) detected by a speed detector 18 to reduce a path searching frequency of the peripheral base station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CDMA (Code
The present invention relates to a mobile radio terminal used in a mobile radio communication system such as a mobile phone system or a mobile phone system adopting a Division Multiple Access (Division Multiple Access) system.

[0002]

2. Description of the Related Art As is well known, in a wireless communication terminal of a CDMA mobile wireless communication system, in order to suppress power consumption and extend continuous operation time, a control for performing an intermittent reception operation during standby is performed.

In other words, the receiver is operated in accordance with the reception timing of the periodically transmitted paging information, and the reception operation is not performed at other times, so that the power supply to each terminal is minimized. I have. Here, in order to suppress the power consumption during standby and extend the continuous operation time, it is important to shorten the operation time of the receiving unit as much as possible.

On the other hand, even in the standby mode, the timing and strength of a path to be received by a wireless communication terminal change due to movement or fading, so that the path timing and strength of the path are constantly maintained in order to maintain good reception characteristics. Detection must be performed periodically.

[0005] In addition, due to the movement of the radio communication terminal, the status of a multipath arriving from a nearby base station in addition to a multipath arriving from the nearest base station changes every moment. Therefore, in order to always maintain good reception characteristics, it is necessary to know in advance the multipath coming from the surrounding base station in preparation for a handover for switching the base station to be communicated as necessary. It is.

For this reason, conventionally, a mobile radio terminal performs a path search process for periodically detecting not only a base station to be communicated but also a multipath of a peripheral base station during intermittent reception during standby.

However, in the conventional mobile radio terminal,
Since a plurality of receivers are used for RAKE reception, power consumption is basically large, and reduction of power consumption has been a major issue.

[0008]

The conventional CDMA mobile radio terminal has a problem that the power consumption is basically large because a plurality of receivers are used for RAKE reception. The present invention has been made to solve the above problem, and has as its object to provide a mobile radio terminal capable of reducing power consumption and extending continuous operation time.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a mobile radio terminal used in a mobile radio communication system for performing radio communication according to a CDMA system. Search means for intermittently detecting a multipath, selection means for selecting a communication partner based on the detection result of the search means, reception means for receiving a transmission signal from the communication partner selected by the selection means, Power level detection means for detecting the power level from the reception result of the reception means, and area detection means for detecting the size of the communicable area formed by the communication partner selected by the selection means from the reception result of the reception means Based on the power level detected by the power level detection means and the size of the area detected by the area detection means. ; And a detection target setting means for setting a communication partner to be output target was set to configure.

In the mobile radio terminal having the above configuration, the multipath is intermittently detected based on the reception power level of the communication partner selected by the selection means and the size of the area where the communication partner can communicate. A communication partner to be detected by the search means is set.

Therefore, according to the mobile radio terminal having the above configuration, the communication partner to be subjected to multipath detection is set in the search unit based on the positional relationship with the communication partner mainly performing communication selected by the selection unit. Therefore, it is possible to prevent unnecessary operation such as the search means detecting a multipath from another communication partner, despite the fact that the distance to the communication partner performing communication is short and sufficient stable communication can be performed. In addition, power consumption can be reduced and continuous operation time can be extended.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a CDMA mobile radio terminal apparatus according to an embodiment of the present invention. In particular, here, a description will be given mainly of a receiving system according to the present invention.

The transmitting device 12 modulates transmission data such as digitized voice and data by a digital modulation method such as PSK modulation, spreads the modulated data using a spreading code, and generates a wideband base signal. Convert to band signal.

The transmitting apparatus 12 up-converts the spread baseband signal into a radio frequency signal and inputs the signal to the antenna 10 through the duplexer 11. The input radio frequency signal is transmitted to the antenna 10
It is radiated further into space and transmitted to a base station (not shown).

On the other hand, the radio signal transmitted from the base station is received by the antenna 10 and input to the receiving device 13 through the duplexer 11. The receiving device 13 includes a radio circuit 14, an intermediate frequency circuit 15, and a rake (rake) receiver 16.

In the radio circuit 14, the radio signal received from the duplexer 11 is input to the attenuator 14a, where it is attenuated by a predetermined amount. The signal that has passed through the attenuator 14a is amplified to a predetermined level by an amplifier 14b, mixed with a local oscillation signal generated by a frequency synthesizer 14d by a mixer 14c, and down-converted to an intermediate frequency.

The signal down-converted to the intermediate frequency is input to an intermediate frequency circuit 15 and amplified to a predetermined level by an amplifier 15a. The result of the amplification is input to a band-pass filter (BPF) 15b, from which only a desired band passes and input to a mixer 15c.

In the mixer 15c, the bandpass filter 1
The signal that has passed through 5b is mixed with the signal generated by frequency synthesizer 15d, and is converted into a baseband signal. This baseband signal is converted into a digital signal by an A / D converter (A / D) 15e,
It is input to the KE receiver 16.

The RAKE receiver 16 includes a searcher 16a
, Fingers 16b, 16c, 16d, and a symbol combiner 16e, and the digital signal is input to the searcher 16a and the fingers 16b, 16c, 16d, respectively.

The searcher 16a is provided with a control unit 100 to be described later.
, And a despreading timing is designated. The digital signal is subjected to despreading processing based on the information, and a base station to be received (hereinafter referred to as a receiving base station) and a receiving base station are designated. A signal that arrives on a plurality of routes from a base station located in the vicinity of the base station (hereinafter, referred to as a peripheral base station) to its own terminal, that is, a so-called multipath, is detected, and the detection result is notified to the control unit 100.

The fingers 16b, 16c and 16d are assigned paths to be received by the control unit 100 designating the type of spreading code used for despreading and the despreading timing.

The fingers 16b, 16c, 16d
Performs despreading processing on the digital signal based on information specified by the control unit 100, obtains a multipath despreading result from the receiving base station, and outputs the result to the symbol combiner 16e.

The symbol synthesizer 16e includes a finger 16
b, 16c and 16d, the multipath components respectively despread are symbol-synthesized in consideration of the despread timing assigned to each finger 16b, 16c and 16d,
Output to the signal processing unit 17.

The signal processing unit 17 includes a symbol synthesizer 16e
A predetermined demodulation process is performed on the result of combining to reproduce the received data. In addition, the signal processing unit 17 includes the control unit 100
, The power level of the signal obtained by RAKE-combining the multipath of the receiving base station (hereinafter referred to as the receiving base station power level) p
, A function of detecting information on neighboring base stations transmitted from the receiving base station through the broadcast channel, and a transmission power value of the receiving base station transmitted through the broadcast channel. A function of determining a radius (hereinafter, referred to as a receiving base station cell radius) r.

The detection results are notified to the control unit 100. The information on the peripheral base station includes information indicating the type of a spreading code used by the peripheral base station in the despreading process and the timing of despreading.

The speed detecting circuit 18 detects the moving speed v of the mobile radio terminal and notifies the control unit 100 of the detected speed. As a method of detecting the moving speed v, the fading pitch of the received signal is monitored, and detection is performed based on the monitoring result.

The control unit 100 includes a CPU, a ROM and an R
AM, etc., wherein the CPU is the RO
M for controlling the respective units of the mobile radio terminal device in accordance with a control program and control data stored in the M. For example, based on information on a path detected by the searcher 16a, the fingers 16b, 16c, 16d And performs control related to reception path allocation and handover.

The control unit 100 controls the searcher 16a based on information on the peripheral base station detected by the signal processing unit 17 and the like to detect multipath from the receiving base station and the peripheral base station. Has functions.

Then, with this control function, the control unit 100
Using its own timer function, timers T1, T2, T3,
Received base station power level p detected by signal processing unit 17
The multipath detection function of the searcher 16a intermittently operates based on the reception base station cell radius r, the moving speed v detected by the speed detection circuit 18, and the parameters stored in the storage unit 200 described later. Let it.

The storage unit 200 is a recording medium such as a ROM and a RAM, and has an area for storing various information such as telephone directory data which can be arbitrarily recorded by a user. Threshold Pth, cell radius threshold R
th, moving speed threshold Vth and times t1, t2, t3
It has a parameter storage area 200a for storing parameters such as (t3>t1> t2).

Although not shown in FIG. 1, as a component of the present apparatus, there is a power supply section which supplies power for operating the above-described sections and has a battery which can be repeatedly charged and discharged.

Next, the operation of the mobile radio terminal having the above configuration will be described. In the following, the fingers 16b,
The description of the control operation for allocating the multipath from the receiving base station to 16c and 16d is omitted, and the control operation relating to the detection of the multipath will be described with reference to FIG.

This control operation is performed after the control unit 100 allocates a multipath from the receiving base station to the fingers 16b, 16c, and 16d, and becomes ready to receive signals from the receiving base station. Done by

First, in step 2a, the power level p of the receiving base station detected by the signal processing unit 17, the cell radius r of the receiving base station, and the moving speed v detected by the speed detecting circuit 18 are obtained. T1, T2, and T3 are activated to start timing, and the process proceeds to step 2b. In addition,
Here, if the timers T1, T2, and T3 have already been started, their count values are reset, and
The count is restarted from "0".

In step 2b, the receiving base station power level p, the receiving base station cell radius r, and the moving speed v obtained in step 2a are p> Pth, r> Rth, and v <V, respectively.
It is determined whether or not the condition of th is satisfied. here,
If all of the above conditions are satisfied, step 2i
The process proceeds to step 2c if all are not satisfied.

In step 2c, it is determined whether or not the count value of the timer T2 is equal to or longer than t2. Here, if the count value of the timer T2 is equal to or more than t2, the process proceeds to step 2d, while if the count value of the timer T2 is less than t2, the process returns to step 2c.

At step 2d, information on the peripheral base stations detected by the signal processing section 17 and the fingers 16b, 16
c, 16d, the searcher 16
By controlling a, a multipath from the receiving base station and the neighboring base stations is detected as shown in FIG. 3A, and the process proceeds to step 2e.

The path information detected here is used for path reassignment processing and handover processing. Also,
In step 2d, the count value of the timer T2 is reset, and the count is restarted from "0".

In step 2e, it is determined whether or not the count value of the timer T3 is equal to or longer than t3 in order to determine whether or not a cycle t3 for reviewing the cycle of the path search control has arrived.

Here, if the count value of the timer T3 is equal to or more than t3, the process shifts to step 2a and the process is executed again from the beginning. On the other hand, if the count value of the timer T3 is less than t3, the process proceeds to step 2f.

In step 2f, the fingers 16b, 16
It is determined whether or not a handover is required based on the reception status by c and 16d and the status of the path detected in step 2d. Here, when the necessity of the handover occurs, the process proceeds to step 2h, and when the necessity of the handover does not occur, the process proceeds to step 2g.

In step 2g, it is determined whether or not the operation of the mobile radio terminal has been terminated by, for example, turning off the power of the user. Here, when the operation is to be ended, the process is ended, while when the operation is to be continued, the process proceeds to step 2c.

In step 2h, control is performed to reassign the paths detected by the control in step 2d or step 2j or step 21 described later to the fingers 16b, 16c and 16d. Re-execute the process from the beginning.

On the other hand, in step 2i, it is determined whether or not the count value of the timer T1 is equal to or longer than t1 longer than the time t2. Here, when the count value of the timer T1 is equal to or more than t1, the process shifts to step 2j. On the other hand, when the count value of the timer T1 is less than t1, the process shifts to step 2k.

In step 2j, information on the peripheral base stations detected by the signal processing section 17 and the fingers 16b, 16b
c, 16d, the searcher 16
By controlling a, as shown in FIG. 3A, the multipath from the receiving base station and the neighboring base stations is detected, and the process proceeds to step 2m.

The path information detected here is used for path reallocation processing and handover processing. Also,
In step 2j, the count values of the timers T1 and T2 are reset, and the count is restarted from "0".

At step 2k, it is determined whether or not the count value of the timer T2 is equal to or longer than t2. Here, when the count value of the timer T2 is equal to or more than t2, the process proceeds to step 21. On the other hand, when the count value of the timer T2 is less than t2, the process returns to step 2i.

In step 21, the fingers 16b, 16
c, 16d, the searcher 16
By controlling a, the multipath of the receiving base station is detected as shown in FIG.

The path information detected here is used for path reassignment processing and handover processing. Also,
In step 21, the count value of the timer T2 is reset and the count is restarted from "0".

In step 2m, it is determined whether or not the count value of the timer T3 is equal to or longer than t3 in order to determine whether or not the cycle t3 for reviewing the path search control cycle has arrived.

If the count value of the timer T3 is equal to or longer than t3, the process shifts to step 2a, and the process is executed again from the beginning. On the other hand, when the count value of the timer T3 is less than t3, the process proceeds to step 2n.

In step 2n, the fingers 16b, 16
It is determined whether or not a handover is necessary based on the reception status by c and 16d and the status of the path detected in step 2j or step 21. Here, when the necessity of the handover occurs, the process proceeds to step 2h, and when the necessity of the handover does not occur, the process proceeds to step 2o.

In step 2o, it is determined whether or not the operation of the mobile radio terminal has been terminated by, for example, turning off the power of the user. Here, when the operation is to be ended, the process is ended, while when the operation is to be continued, the process proceeds to step 2i.

As described above, in the mobile radio terminal having the above configuration, the receiving base station power level p, the receiving base station cell radius r,
When the moving speed v is p> Pth, r> Rth, v <
Vth is satisfied, that is, the radius r of the cell formed by the receiving base station is larger than Rth, and the received power level p from the receiving base station is larger than Pth. In a state where it is estimated that the user is in the vicinity and the moving speed v is lower than Vth and the vehicle is moving at a low speed, it is estimated that there will be no trouble in communication with the receiving base station for a while. Therefore, the processing starting from step 2i reduces the frequency of the path search of the peripheral base station.

Therefore, according to the mobile radio terminal having the above configuration, in a situation where it is difficult to newly assign a path to a neighboring base station, the frequency of the process of detecting a multipath from the neighboring base station is reduced. Therefore, the power consumption related to the path search can be reduced, and the continuous operation time can be extended.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the frequency of the process of detecting the moving speed v and detecting the multipath from the peripheral base station is reduced on the condition that the mobile radio terminal is moving at a low speed. However, the moving speed does not always have to be the above condition. Even if only the receiving base station power level p and the receiving base station cell radius r are considered without considering the moving speed, the power consumption related to the path search can be reduced, and the continuous operation time can be extended. It goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0057]

As described above, according to the present invention, based on the reception power level of the communication partner selected by the selection means and the size of the area where the communication partner can communicate,
A communication partner to be detected by a search means for intermittently detecting a multipath is set.

Therefore, according to the present invention, the communication partner to be subjected to multipath detection is set to the search unit based on the positional relationship with the communication partner mainly performing communication selected by the selection unit. Although the distance to the communicating party is short and communication can be performed sufficiently stably, the search means can prevent useless operations such as detecting multipaths from other communicating parties. It is possible to provide a mobile radio terminal capable of reducing the number of continuous operation times.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a configuration of an embodiment of a mobile radio terminal according to the present invention.

FIG. 2 is a flowchart for explaining path search control of the mobile wireless terminal shown in FIG. 1;

FIG. 3 is a diagram for explaining an intermittent operation of the path search control shown in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Antenna 11 ... Duplexer 12 ... Transmitting device 13 ... Receiving device 14 ... Wireless circuit 14a ... Attenuator 14b ... Amplifier 14c ... Mixer 14d ... Frequency synthesizer 15 ... Intermediate frequency circuit 15a ... Amplifier 15b ... Bandpass filter (BPF) 15c ... Mixer 15d ... Frequency synthesizer 15e ... A / D converter (A / D) 16 ... RAKE receiver 16a ... Searcher 16b, 16c, 16d ... Finger 16e ... Symbol synthesizer 17 ... Signal processing unit 18 ... Speed detection circuit 100 ... Control unit 200: storage unit 200a: parameter storage area

Claims (5)

[Claims] 1. A CDMA (Code Division Multiple Acc)
ess) In a mobile radio terminal used in a mobile radio communication system that performs radio communication by a method, a search means for intermittently detecting a multipath from a communication partner capable of performing the radio communication, and Selecting means for selecting a communication partner; receiving means for receiving a transmission signal from the communication partner selected by the selecting means; power level detecting means for detecting a power level from a reception result of the receiving means; An area detection means for detecting a size of a communicable area formed by the communication partner selected by the selection means from a reception result of the reception means; a power level detected by the power level detection means; A detection target setting for setting a communication partner to be a multipath detection target in the search means based on the size of the area detected by the area detection means. Mobile radio terminal characterized by and means. 2. The power supply apparatus according to claim 1, wherein the detection target setting unit is configured to set the power level detected by the power level detection unit to a first preset power level.
When the size of the area detected by the area detecting means is equal to or more than a second threshold value or more,
2. The mobile radio terminal according to claim 1, wherein the search unit is set to preferentially detect a multipath from a communication partner selected by the selection unit. 3. A moving speed detecting means for detecting a moving speed, wherein the detection target setting means comprises: a power level detected by the power level detecting means; a size of an area detected by the area detecting means; 2. The apparatus according to claim 1, further comprising: a detection target setting unit configured to set a communication partner to be a multipath detection target in the search unit based on the moving speed detected by the moving speed detection unit. 3. Mobile radio terminal. 4. The apparatus according to claim 1, wherein the detection target setting unit is configured to set the power level detected by the power level detection unit to a first preset power level.
And the size of the area detected by the area detecting means is equal to or greater than a second threshold value set in advance, and the moving speed detected by the moving speed detecting means is smaller than a third threshold value. 4. The mobile radio terminal according to claim 3, wherein the search means is set to preferentially detect a multipath from a communication partner selected by the selection means. 5. The area detecting means detects the transmission power of the communication partner selected by the selecting means from the reception result of the receiving means, and forms the communication partner selected by the selecting means from the detection result. The mobile radio terminal according to any one of claims 1 to 4, wherein the size of a communicable area is detected.