JP2002198865A - Mobile radio terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile radio terminal of a CDMA system which is capable of improving communication quality and saving power consumption by performing efficient assignment of a path. SOLUTION: A control section 100 for integrally controlling each section of the terminal records the receiving quality of a plurality of receivable paths notified from a searcher 13 and fingers 16b, 16c and 16d in an averaging table storage area 200a, averages the stored receiving quality by averaging times corresponding to a traveling speed detected by a speed detecting circuit 18 for each path, and records the result of averaged receiving quality of each path in a path table storage area 200b periodically. When the receiving qualities of paths during received by the fingers 16b, 16c and 16d are deteriorated, a path with better receiving quality is searched in the averaged result of the receiving quality of each path recorded in the area 200b, and the searched path is substituted for the path with deteriorated receiving quality to receive.

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, a mobile radio terminal adopting the CDMA system includes a plurality of receivers called fingers, and one communication is communicated through a plurality of paths using the plurality of receivers. Therefore, there is an advantage that not only the communication quality is better than other communication schemes that perform communication using only one path, but also that high-speed movement can be supported.

The assignment of a path to a finger is performed by a circuit called a searcher. The searcher detects a plurality of paths (hereinafter, referred to as candidate paths) that can be received by its own terminal, and allocates the fingers to the fingers in order from a path having a higher received power level among the plurality of candidate paths.

[0004] For example, when the radio wave propagation environment changes due to the movement of the terminal device and the reception quality of a path assigned to a finger (hereinafter referred to as a reception path) decreases, the reception quality decreases. For the finger to which the reception path is assigned, a path reassignment process is performed in which a promising candidate path is selected from the remaining candidate paths and assigned to a new path.

[0005] By the way, as the moving speed of the mobile radio terminal device is higher, the radio wave environment changes more drastically. Therefore, when the mobile radio terminal device moves at high speed, the process of re-assigning the path to the finger frequently occurs.

However, since there is no stable radio wave environment at the time of high-speed movement, there is a high possibility that the detected candidate path is not always an effective path capable of performing stable communication, and the reassignment of the path may degrade the communication quality. Is high.

For this reason, in the conventional mobile radio terminal,
At the time of high-speed movement, not only is the inefficient path assignment process performed, but the problem also arises that the process consumes useless power.

In particular, a mobile radio terminal of the CDMA system has a large power consumption because of having a plurality of fingers, and a reduction in power consumption is a major problem. For the system, waste of power consumption during high-speed movement was a major problem.

[0009]

In the conventional mobile radio terminal of the CDMA system, when moving at high speed, not only the inefficient path assignment processing is performed, but also unnecessary power is consumed by the processing. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and it is possible to perform efficient path assignment processing to improve communication quality and prevent waste of power consumption even during high-speed movement. It is an object of the present invention to provide a possible CDMA mobile radio terminal.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a mobile radio terminal used in a mobile radio communication system for performing radio communication according to a CDMA system. Detecting means, moving speed detecting means for detecting the moving speed, averaging count determining means for determining the number of samples according to the moving speed detected by the moving speed detecting means, and a plurality of The quality averaging means for averaging the reception quality of the path using the number of samples for each path, a plurality of reception means for performing rake reception, and the reception quality of the path received by this reception means If it deteriorates below a certain level,
On the basis of the averaging result of the quality averaging means, a path suitable for reception is obtained, and a path allocating means for controlling the receiving means to receive the obtained path is provided.

In the mobile radio terminal having the above configuration, the reception qualities of a plurality of receivable paths are averaged using the number of samples corresponding to the moving speed for each path, and the reception quality of the path being received by the receiving means is determined by a predetermined value. If the signal quality deteriorates below the level, a path having good reception quality is obtained from the averaging result, and this path is received in place of the path having poor reception quality.

[0013] Therefore, according to the mobile radio terminal having the above configuration, a path suitable for reception is allocated based on the reception quality of the path averaged according to the moving speed. Assigning a path with temporarily improved reception quality or allocating a path with temporarily deteriorated reception quality does not cause frequent path assignments, and when moving at low speed,
Since the number of times of averaging is set to be small, the path following is quickly performed.

[0014] Therefore, it is possible to quickly assign a path or assign a path enabling stable reception in accordance with the moving speed, thereby improving the communication quality by performing efficient path assignment processing and improving power consumption. Waste can be prevented.

[0015]

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, and Ra
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 includes a control unit 100 described later.
Based on the instruction from
Inverse calculation using various spreading codes is performed to detect signals arriving from the base station to the own terminal via a plurality of paths, so-called multipath.

Then, the searcher 16a obtains the detected reception quality level (for example, RSCP, RxAGC, etc.) of each path, the despread timing of each path, and the identification information of the base station which is the transmission source, and detects these information. The control unit 100 is notified as path information.

The fingers 16b, 16c and 16d are assigned paths to be received from the control unit 100. In this assignment, the type of the spreading code used for despreading and the despreading timing are designated, whereby the fingers 16b, 1
6c and 16d despread the digital signal using the same spreading code used for spreading on the transmitting side,
The result of the despreading is output to the symbol combiner 16e.

The fingers 16b, 16c, 16d
Is the reception quality level (eg, R
SCP, RxAGC, etc.) and the identification information of the base station that is the transmission source of the receiving path, and associates this information with the type of spreading code assigned to itself and the despreading timing, The control unit 100 is notified as reception path information.

The symbol combiner 16e includes a finger 16
The multipath components despread by b, 16c, and 16d are symbol-synthesized in consideration of the despread timing assigned to each of the fingers 16b, 16c, and 16d.

The signal that has been symbol-synthesized by the symbol synthesizer 16e is subjected to demodulation processing corresponding to digital modulation on the transmission side by a signal processing unit 17 at the subsequent stage, and the received data is reproduced.

The speed detecting circuit 18 detects the moving speed of the mobile radio terminal. As a moving speed detection method, a fading pitch of a 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
In accordance with a control program and control data stored in M, each section of the mobile wireless terminal device is controlled in an integrated manner. For example, the assignment of reception paths to the fingers 16b, 16c, and 16d is performed.

In this receiving path assignment control, the control unit 1
00, based on the detected path information notified from the searcher 16a and the received path information notified from the fingers 16b, 16c, 16d, determines the reception quality of the path that can be received by the mobile radio terminal device, Averaging is performed with the number of times of averaging based on the moving speed detected at 18, and an allocation path is determined based on the averaging result.

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 that can be arbitrarily recorded by a user. It has a table storage area 200a and a path table storage area 200b.

The averaging table storage area 200a is an area in which the control unit 100 reads and writes the storage contents. As shown in FIG. 2, seven path search results are recorded for each base station.

The path search results indicate that the reception quality (eg, RSCP, Rx
AGC) is recorded. When the seven path search results are recorded, the path search results are updated to the new path search results in order from the oldest path search result.

The path table storage area 200b is an area in which the storage contents are read and written by the control unit 100. As shown in FIG. 3, for each base station, the type of spreading code used for communication, the mobile radio terminal Status information indicating whether or not the device is used for communication, carrier RSS
I, and path information on the path to the corresponding base station are recorded.

The path information includes the number of paths to the corresponding base station and the averaging state information of each path. The averaging state information indicates the reception quality (eg, RSCP, RSCP) of the corresponding path.
xAGC) and the fingers 16b, 1
The reception path flag indicates whether reception is being performed in any of 6c and 16d.

Although not shown in FIG. 1, there is a power supply unit having a battery that supplies power for operating the above-described units and that can be repeatedly charged and discharged as a component of the apparatus.

Next, with reference to FIG. 4 to FIG. 7, the operation of controlling the allocation of the reception path of the mobile radio terminal having the above configuration will be described. The control operation described below is performed by the control unit 10
Done by 0.

First, the process of determining the number of times of averaging will be described. FIG. 4 is a flowchart illustrating this process.
When the power of the mobile wireless terminal device is turned on, the control unit 1
00 until the power is turned off.

In step 4a, the moving speed detected here is fetched from the speed detecting circuit 18, and in step 4b
Move to In step 4b, the number of times of averaging is determined according to the moving speed captured in step 4a. Here, the number of times of averaging is set to be larger as the moving speed is higher.

For example, when the moving speed is "0 km / h", it is regarded that the vehicle is in the stop state, and the number of times of averaging is set to "1". If the moving speed is more than “0 km / h” and less than “10 km / h”, the averaging count is set to “3”.

When the moving speed is not less than "10 km / h" and less than "40 km / h", the number of times of averaging is set to "5", and when the moving speed is "40 km / h" or more, Sets the number of times of averaging to “7”.

Then, in step 4c, step 4b
It is determined whether or not a predetermined time has elapsed from the previous number of times of averaging and a review cycle of the number of times of averaging has arrived. Here, when the review cycle has arrived, the process shifts to step 4a to review the number of times of averaging. On the other hand, if the review cycle has not arrived, the process proceeds to step 4d.

In step 4d, it is determined whether or not the power has been turned off. Here, if the power is set to OFF, the process is terminated, while the power is turned OFF.
If not, the process proceeds to step 4c.

Next, a description will be given of the path assignment processing immediately after the power is turned on. FIG. 5 is a flowchart illustrating this process. This process is performed by the control unit 100 immediately after the power of the mobile wireless terminal device is turned on.

In step 5a, based on the detected path information notified from the searcher 16a, the reception quality of the path receivable by the mobile radio terminal device is recorded as a path search result in the averaging table storage area 200a. Move to step 5b. Here, as shown in FIG. 3, the reception quality of the receivable path is recorded for each base station.

In step 5b, the number of path search results recorded in the averaging table storage area 200a is
It is determined whether or not there is the number of times of averaging determined in the process. Here, if there is only the number of times of averaging, the process proceeds to step 5c.
The process proceeds to step 5a, where the path search result is fetched.

In step 5c, based on the path search result recorded in the averaging table storage area 200a,
The reception quality is averaged by the averaging number for each base station having the same source and the same despreading timing, that is, for each same path.

The averaging result of the reception quality for each path obtained in this way is stored in the path table storage area 200.
record in the registry of the corresponding base station in step b.
Move to d.

At this time, the type of spreading code, carrier R
Information such as SSI is also recorded, and information indicating the despread timing is recorded for each pass.

In step 5d, three optimal paths for reception are obtained by referring to the result of averaging the reception quality for each path stored in the path table storage area 200b. And
To receive the obtained three paths, the finger 16
One path is assigned to each of b, 16c and 16d.

At the same time, in the path table storage area 200b, "1" indicating that the base station is used for communication is set in the status information of each base station corresponding to the allocated three paths, and the other base stations are set. Statu
In the s information, “0” indicating that it is not used for communication is set.

The receiving path flags corresponding to the three allocated paths are set to “1” indicating reception, and the receiving path flags of the other paths are set to “0” indicating non-receiving. To end.

After the first path is allocated in this way, the control unit 100 thereafter executes a process for averaging the reception quality for each path as shown in FIG. 6 at a predetermined cycle. At the same time, the control unit 100 monitors the reception quality of the fingers 16b, 16c, and 16d,
When the reception quality degrades from a preset level, a path reallocation process is executed as shown in FIG.

First, the process of averaging the reception quality for each path shown in FIG. 6 will be described. In step 6a, the detected path information notified from the searcher 16a and the finger 16
Based on the reception path information notified from b, 16c, and 16d, the reception quality of the path receivable by the mobile radio terminal is recorded as a path search result in the averaging table storage area 200a, and the process proceeds to step 6b. I do.

In this recording, path status information indicating the reception quality of each path is recorded so that the same path is not duplicated. When seven path search results are recorded, the oldest path search results are recorded in order. Updated to new path search results.

In step 6b, among the path search results recorded in the averaging table storage area 200a, FIG.
The reception quality is averaged for each same path based on the latest path search result corresponding to the number of times of averaging determined in the above processing.

The averaging result of the reception quality for each path obtained in this way is stored in the path table storage area 200.
The information is recorded in the registry of the base station corresponding to b, and the process ends.

At this time, in the path table storage area 200b, the type of the spreading code and the carrier R are stored for each base station.
Information such as SSI is also recorded, and information indicating the despread timing is recorded for each pass.

Next, the path reallocation processing shown in FIG. 7 will be described. First, in step 7a, an optimal path for reception is determined by referring to the reception quality averaging result for each path stored in the path table storage area 200b, and the process proceeds to step 7b.

Here, based on the Status information in the path table storage area 200b and the reception path flag, the path of the base station used for communication and the path not currently assigned to the fingers 16b, 16c, 16d Is preferentially requested from

In step 7b, paths are reassigned to the fingers 16b, 16c, and 16d whose reception quality has deteriorated so as to receive the path obtained in step 7a. At the same time, the path table storage area 200
b, "1" indicating that the status information of the base station corresponding to the newly assigned path is used for communication.
Is set, and “0” is set in the status information of the base station not used for communication.

Then, the receiving path flag corresponding to the newly allocated path is set to “1” indicating reception, and the receiving path flag of the path not receiving due to the new allocation is set to “0” indicating Then, the process ends.

If the reception quality of the path determined in step 7a is lower than the reception quality of the receiving path whose reception quality has deteriorated, in step 7b, the path determined in step 7a is not newly assigned. , So that the receiving path is continuously received.

As described above, in the mobile radio terminal having the above-described configuration, the reception qualities of a plurality of receivable paths are periodically recorded in the averaging table storage area 200a, and the reception qualities are recorded for each path. And averages the reception quality of each path in the path table storage area 200b periodically.

Then, the fingers 16b, 16c, 16d
When the reception quality of the path being received is degraded, a path having good reception quality is obtained from the result of averaging the reception quality of each path recorded in the path table storage area 200b, and the path having the deteriorated reception quality is determined. Instead of receiving.

In other words, a path suitable for reception is allocated based on the reception quality of the path averaged according to the moving speed. Therefore, even when moving at a high speed, the path having temporarily improved reception quality is used. Or assign
There is no frequent occurrence of path assignment such as a failure to assign a path with temporarily deteriorated reception quality. In addition, during low-speed movement, the number of times of averaging is set to be small, so that path following is quickly performed.

Therefore, according to the mobile radio terminal having the above configuration, it is possible to allocate a path quickly and allocate a path enabling stable reception according to the moving speed, and perform efficient path allocation processing. Communication quality and power consumption can be prevented.

In the mobile radio terminal having the above configuration,
The search path information of the searcher 16a and the fingers 16b, 1
6c and 16d, the information about the same path is duplicated and the averaging table storage area 20 is duplicated.
0a so that the searcher 16
The finger 16b, 16c, 16d
Even if the information of the path being received is included, the averaging process and the like for the same path are not performed repeatedly.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the detection path information of the searcher 16a and the fingers 16b, 16c,
The reception quality is averaged for all paths receivable by the mobile radio terminal based on the reception path information of the searcher 16d. Instead, the detection path information of the searcher 16a and the fingers 16b and 16c are averaged. , 16d, the control unit 100 averages the reception quality only for the paths not received by the fingers 16b, 16c, 16d based on the information (for example, reception path information) for identifying the path being received. A path suitable for reception may be obtained from the result.

According to the averaging process and the path allocating process, the averaging process is performed only on the path that has not been received, and the path is allocated based on the averaging process. The control unit 100 can perform path reassignment quickly and with a low processing amount as compared with a case where a path suitable for reception is obtained. It goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0072]

As described above, according to the present invention, the reception qualities of a plurality of receivable paths are averaged using the number of samples corresponding to the moving speed for each path, and the reception means is used to determine the reception quality of the path being received. When the reception quality deteriorates below a predetermined level, a path having good reception quality is obtained from the above-mentioned averaging result, and this path is received in place of the path whose reception quality has deteriorated.

In other words, a path suitable for reception is allocated based on the reception quality of the path averaged according to the moving speed. Therefore, even during high-speed movement, a path having temporarily improved reception quality is assigned. Or assign
There is no frequent path assignment, such as losing the path with temporarily deteriorated reception quality, and at the time of low-speed movement, the number of averaging is set small,
Path following will be performed quickly.

Therefore, according to the present invention, it is possible to quickly assign a path or assign a path that enables stable reception according to the moving speed, thereby improving the communication quality by performing efficient path assignment processing. In addition, it is possible to provide a mobile radio terminal capable of preventing waste of power consumption.

[Brief description of the drawings]

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

FIG. 2 is a view for explaining information recorded in an averaging table storage area of the mobile wireless terminal device shown in FIG. 1;

FIG. 3 is an exemplary view for explaining information recorded in a path table storage area of the mobile wireless terminal device shown in FIG. 1;

FIG. 4 is a flowchart for explaining a process for determining the number of times of averaging according to the moving speed of the mobile wireless terminal device shown in FIG. 1;

FIG. 5 is a flowchart for explaining a reception path assignment process immediately after power-on of the mobile wireless terminal device shown in FIG. 1;

FIG. 6 is a flowchart for explaining an averaging process of reception quality for each path of the mobile wireless terminal device shown in FIG. 1;

FIG. 7 is a flowchart for explaining detection of a path suitable for reception by the mobile radio terminal apparatus shown in FIG. 1 and processing for allocating the path.

[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: averaging table storage area 200b: path table storage area

Claims (3)

[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 according to the method, a path detecting means for detecting a plurality of receivable paths; a moving speed detecting means for detecting a moving speed; Averaging count determining means for determining the number of samples according to the detected moving speed, and quality for averaging reception quality of a plurality of paths detected by the path detecting means using the number of samples for each path. Averaging means, a plurality of receiving means for performing rake reception, and an averaging result of the quality averaging means when the reception quality of a path received by the receiving means has deteriorated below a predetermined level. And a path allocating means for controlling the receiving means so as to receive the determined path based on the path. 2. A reception path quality detection means for detecting reception quality of a path being received from reception results of the plurality of reception means, and a reception quality detected by the reception path quality detection means for each path. The reception path quality averaging means for averaging using only the number of samples, the path allocating means, when the reception quality of the path received by the receiving means has deteriorated below a predetermined level, Based on the averaging result of the quality averaging unit and the averaging result of the reception path quality averaging unit, determine a path suitable for reception, and control the receiving unit to receive the determined path. The mobile radio terminal according to claim 1, wherein: 3. The quality averaging means, for a plurality of paths detected by the path detection means, for only paths other than the path received by the reception means, the reception quality is determined for each path. The mobile radio terminal according to claim 1 or 2, wherein averaging is performed using only the number of samples.