JPH11289289A - Radio terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio terminal capable of shortening receiving time and extending battery life in accordance with the shortening of receiving time by reducing the receiving frequency of signals from peripheral cells. SOLUTION: The radio terminal continuously measures the electric field strength of its own cell and that of peripheral cells at prescribed timing until a timer times up (steps S43 to S47). When the electric field strength of its own cell is dropped to <=L1, a flag (f) is set to '1' (step S46). When each of plural measured results measured by the timer for prescribed time T3 up to the time-up of the timer is f=0, namely is larger than a certain fixed electric field strength L1, the terminal receives only a signal from its own cell and does not receive signals from peripheral cells (steps S49, S50). Consequently the receiving frequency of signals from peripheral cells can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless terminal such as a portable telephone, and more particularly to a standby method for the wireless terminal.

[0002]

2. Description of the Related Art FIG. 8 is an example showing a conventional receiving system. The wireless terminal must monitor whether there is a call to its own device, but at what timing a call signal to its own device comes in synchronization with a received signal from the base station in advance Therefore, at that timing, the receiving circuit is turned on for a fixed time T2 and the signal is received.
This reception is performed at a period of an interval T1.

By the way, during T2, that is, A, B,.
During this period, a signal is received from the base station of the cell in which the own device is present and waiting (own cell), demodulated to monitor whether there is a calling signal to the own device, and at the same time, And the electric field strength of signals from each base station of a cell (peripheral cell) adjacent to the own cell. This is because it is necessary to be able to immediately perform a movement procedure when the own device moves and moves from the own cell to a neighboring cell.

Conventionally, the measurement of the electric field strength of the signal of the peripheral cell has always been performed at a predetermined timing during the period T2. That is, as shown in FIG. 8, after receiving the signal of its own cell, it always receives the signals of two neighboring cells,
For example, the electric field strengths of six signals of adjacent cells are measured at timings M1 to M6, respectively.

[0005] However, for example, in a state where the own device is stationary such as being placed on a desk or the like, the electric field strength of a signal from the base station of the cell in which the own device is awaiting also increases. The electric field strength of the signal from the station hardly changes. That is, the fading phenomenon does not occur. For example, a mobile phone may not move at half a day, or a data terminal may not move at all. In such a situation, it is meaningless to measure the electric field strength of the signal from the base station of the neighboring cell many times, and there is a problem that the power for receiving is wasted.

[0006]

As described above, in the above-mentioned radio terminal, the signal from the base station of the peripheral cell is always transmitted even when the electric field strength of the signal from the base station of the peripheral cell hardly changes. Since the electric field strength was measured upon reception, there was a problem that power for reception was wasted.

Therefore, the present invention eliminates this problem and reduces the number of times signals are received from base stations in neighboring cells, thereby reducing the time required to receive signals and prolonging the battery life. An object is to provide a wireless terminal.

[0008]

According to the present invention, there is provided a radio terminal, comprising: an electric field intensity measuring means for measuring an electric field intensity of a received signal; and a number of times of measuring the electric field intensity of a signal from a peripheral base station by the electric field intensity measuring means. And control means for controlling

In such a configuration, if the number of times of reception of signals from peripheral base stations is reduced, the battery life can be prolonged. Here, the control of the number of times of measurement of the electric field strength of the signal from the peripheral base station by the control means can be performed according to the state of the change of the electric field strength measured by the electric field strength measurement means.

With such a configuration, when the change of the electric field strength of the signal from the base station or the neighboring base station where the own apparatus is present and waiting is small, the number of receptions of the signal from the neighboring base station can be reduced. Therefore, the battery life can be prolonged.

Specifically, for example, there is provided detecting means for detecting that the electric field strength measured by the electric field strength measuring means has dropped below a predetermined level or changed above the predetermined level, and the detection means detects the electric field strength in accordance with the detection result of this detecting means. , The number of times of measurement of the electric field strength of the signal from the peripheral base station can be controlled.

Further, there is provided a fluctuation amount detecting means for detecting a temporal fluctuation amount of the electric field intensity measured by the electric field intensity measuring means,
The number of times of measurement of the electric field strength of the signal from the peripheral base station may be controlled in accordance with the amount of fluctuation detected by the fluctuation amount detecting means.

Further, the radio terminal according to the present invention includes a reception quality measuring means for measuring the reception quality of a signal to be received, and a peripheral base station when the reception quality is determined to be equal to or higher than a predetermined value by the measurement means. And control means for controlling the number of times of measuring the reception quality of the signal from the communication device. Even with such a configuration, it is possible to reduce the number of times signals are received from peripheral base stations, and to prolong battery life.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a radio terminal according to the present invention will be described in detail with reference to the drawings. In the following drawings, the same reference numerals indicate the same or corresponding parts. FIG. 1 shows a circuit configuration of an embodiment of a wireless terminal according to the present invention.

In FIG. 1, an audio signal input from a microphone 11 is input to a time division multiplexing / demultiplexing circuit 13 after being subjected to an encoding process in an encoding circuit 12. The time-division multiplexing / demultiplexing circuit 13 performs slot multiplexing on the control signal supplied from the control circuit (CPU) 14 and the encoded audio signal supplied from the encoding circuit 12, and then performs slot multiplexing.
After being modulated by the modulator 15 to have a predetermined frequency and a predetermined transmission output by the transmission circuit 16, the signal is transmitted from the antenna 18 to the base station through the transmission / reception switch 17.

The signal from the base station received by the antenna 18 is input to the receiving circuit 19 through the transmission / reception switch 17. From the receiving circuit 19, a signal RSSI representing the received electric field strength is supplied to the control circuit (CPU) 14. The signal input to the receiving circuit 19 is amplified and frequency-converted here, then demodulated by the demodulator 20, input to the time-division multiplexing / demultiplexing circuit 13, and demultiplexed for each slot. Among the signals output from the time-division multiplexing / demultiplexing circuit 13, the control signal is input to a control circuit (CPU) 14, and the encoded audio signal is input to a decoding circuit 21. After the decoding process is performed, the speaker 2
2 is provided.

Next, FIG. 2 shows a receiving method according to an embodiment of the present invention. The own device that has previously synchronized with the signal from the base station of the cell (own cell) waiting for the own device during the time period T2 in which a call signal to the own device can enter, that is, A, B,. During this time, the receiving circuit 19 is turned on to perform the receiving operation. During this T2, under the influence of the fading phenomenon in which the electric field strength of the signal received by the own apparatus from the own cell fluctuates with time, as shown in FIG. Although receiving operations M1 to M6 of signals from cells (peripheral cells) adjacent to the cell on which the own device is waiting are performed, the electric field strength of the signal from the own cell is lower than when the own device is stationary. When there is almost no change, as shown in FIG. 2, only the signal receiving operation R from the own cell is performed, and the signal receiving operation from the neighboring cells is not performed.

FIG. 3 shows temporally how the received electric field strength of signals from the own cell and the neighboring cells varies. FIG. 2A is a diagram showing that a so-called fading phenomenon occurs in which the reception electric field strength fluctuates greatly because the wireless terminal is moving, and the reception electric field strength falls below a certain level L1. It means that there is something. FIG. 6B shows that the reception intensity of the received electric field hardly changes because the wireless terminal is stationary, and the electric field intensity is always higher than a certain fixed level L1.

FIG. 4 is a flowchart showing a procedure of processing according to an embodiment of the present invention. After setting the flag f indicating that the electric field strength is equal to or lower than the fixed level L1 to zero (step S41), the radio terminal starts a timer (not shown) at any time to measure the electric field strength of the signal from the own cell. It is started (step S42). Until the timer expires, the electric field strengths of the own cell and the neighboring cells are continuously measured at the timing shown in FIG. 8 (steps S43 to S43).
S47). When the electric field strength of the own cell falls below L1, the flag f is set to 1 (step S4).
6).

And a predetermined time T when the timer expires.
If all of the plurality of measurement results measured during the period 3 are greater than a certain constant electric field strength L1 (as in FIG. 3B), that is, it is determined whether f is 1 (step S48).
When f = 0, then, as shown in FIG. 2, only the signal of the own cell is received and the signals of the neighboring cells are not received (steps S49 to S50). Then, after detecting that the electric field strength of the own cell has dropped to L1 or less (step S50), the reception of signals from the neighboring cells is restarted (steps S41 to S47).

Note that when a plurality of measurement results measured during the predetermined time T3 when the timer expires fall below the constant electric field strength L1 even at least once (in the case of FIG. 3A), Determination of whether f is 1 (Step S48)
When f = 1, the reception of the signals of the neighboring cells is restarted (steps S41 to S47).

As described above, when the electric field strength of the signal from the own cell hardly fluctuates, as shown in FIG. 2, only the receiving operation R of the signal from the own cell is performed, and the receiving operation of the signal from the peripheral cell is performed. Since it is not performed, the reception time can be reduced and the battery life can be prolonged accordingly.

In the above embodiment, the example in which the reception of all the signals of the neighboring cells is stopped has been described. However, it is also effective to receive the signals at a lower frequency instead of every time. An embodiment in which reception is performed at a reduced frequency will be described. FIG. 5 shows a processing procedure in this case.

In this embodiment, the same operation as in FIG. 4 is performed until the timer expires, and when the timer expires, a plurality of measurement results indicate that a certain constant electric field strength L
If it is greater than 1, the operation is performed to measure the electric field strength of the signal of the peripheral cell only once out of three times.

That is, when the timer expires, if all of the plurality of measurement results are greater than a certain constant electric field strength L1, that is, if it is determined whether f is 1, f = 0 (step S48).
In this case, the count is started with the count value j of the counter as 1 (step S51), and the measurement of the electric field strength of the signal of the own cell is performed every time (step S53).
Only when the count value j that changes to 1, 2, and 3 is 1, the electric field intensity of the signal of the peripheral cell is measured (step S55), and the measurement operation is repeated (step S55).
51 to S57). Note that, even during this measurement operation, after detecting that the electric field strength of the own cell has decreased below L1 (step S53), the reception of the signals of the neighboring cells is restarted (steps S41 to S47).

Further, in the above-described embodiment, the method of detecting the fluctuation of the electric field strength is such that the fluctuation of the electric field strength is determined to be large when the electric field strength falls below a certain predetermined electric field strength value L1, A method may be used in which the value ΔL of the difference between the maximum value and the minimum value of the electric field strength is calculated, and when the value ΔL exceeds a predetermined value ΔLs, the fluctuation is determined to be large.

That is, FIG. 6A shows a so-called fading phenomenon in which the received electric field strength fluctuates greatly due to the movement of the radio terminal.
Of the difference between the maximum value and the minimum value of the electric field strength, ie, the variation ΔL
Is larger. FIG. 7B shows that the variation in the electric field strength ΔL during a certain period of time T3 is small when there is almost no change in the received electric field strength because the wireless terminal is stationary.

An embodiment in which the variation ΔL of the electric field strength is detected and the variation is determined to be large when the variation ΔL exceeds a predetermined value ΔLs will be described. FIG. 7 shows a processing procedure in this case.

The initial value of the flag f indicating that the electric field intensity fluctuation amount ΔL is equal to or larger than ΔLs may be any one of zero and one, but counting is started by setting the counter value i of the counter to one ( Step S71), the electric field strength Li of the signal of the own cell is measured (step S72), and f =
If it is 1, the electric field strength of the signal of the peripheral cell is also measured (steps S73 to S74). Field strength Li of own cell signal
However, if it exceeds the maximum value Lmax from the start of counting, the maximum value Lmax is updated by Li (steps S75 to S76), and the electric field strength Li of the signal of the own cell is updated.
However, if it is less than the minimum value Lmin since the start of counting, the minimum value Lmin is updated by Li (steps S77 to S78). The count value i is incremented by 1 (step S79), and this operation is repeated until a predetermined count value is reached.

When a predetermined count value is reached (step S
80), it is determined whether or not the difference ΔL between the maximum value Lmax and the minimum value Lmin is equal to or greater than a predetermined value ΔLs (step S80).
81) If the value is equal to or greater than the predetermined value ΔLs, the flag f is set to 1 (step S82), and in addition to the measurement of the electric field strength Li of the signal of the own cell in the next operation (step S72), the signal f The electric field strength is also measured (steps S73 to S74). On the other hand, the maximum value Lmax and the minimum value Lmin
Is smaller than a predetermined value ΔLs (step S81), if the difference ΔL is smaller than the predetermined value ΔLs, the value of the flag f is set to zero (step S82), and the next operation is performed. Only the electric field strength Li of the signal is measured (step S72), and the electric field strength of the signal of the peripheral cell is not measured.

As described above, also in this embodiment, the number of times signals are received from the base stations of the neighboring cells can be reduced, so that the time required to receive signals can be reduced and the battery life can be extended.

In each of the above embodiments, the embodiment in which the electric field strength of the signal of the own cell is measured and the fluctuation of the electric field strength is detected has been described. However, the electric field strength of the signal of the peripheral cell is measured. , The fluctuation of the electric field strength may be detected.

The present invention can be arbitrarily modified without departing from the gist of the present invention. For example, instead of obtaining the fluctuation amount ΔL, the average value L _ave and the standard deviation σ may be obtained, and the determination may be made in this combination.

Further, in each of the above-described embodiments, an example of the field strength measurement has been described as a means for measuring the reception quality of a signal. However, the present invention is not limited to this, and the ratio of an error bit to a bit of a reception signal (Bit Error Rate) is not limited to this. ). That is, when it is determined that the reception quality measured by the error bit rate is equal to or more than a predetermined value, control can be performed so as to reduce the number of times of measurement of the reception quality of the signal from the peripheral base station.

[0035]

As described above, in the wireless terminal of the present invention, by reducing the number of times of receiving signals from the peripheral base stations, the time for receiving the signals can be reduced and the battery life can be extended. There is an advantage.

[Brief description of the drawings]

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

FIG. 2 is a diagram for explaining a receiving method in one embodiment of the wireless terminal according to the present invention.

FIG. 3 is a diagram showing a change in electric field strength for describing an operation of the wireless terminal according to the embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of one embodiment of the wireless terminal according to the present invention.

FIG. 5 is a flowchart for explaining the operation of another embodiment of the wireless terminal according to the present invention.

FIG. 6 is a diagram showing a change in electric field strength for explaining an operation of a wireless terminal according to still another embodiment of the present invention.

FIG. 7 is a flowchart illustrating the operation of a wireless terminal according to yet another embodiment of the present invention.

FIG. 8 is a diagram for explaining a receiving method in a conventional wireless terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Microphone 12 ... Encoding circuit 13 ... Time-division multiplexing / separation circuit 14 ... Control circuit (CPU) 15 ... Modulator 16 ... Transmission circuit 17 ... Transmission / reception switch 18 ... Antenna 19 ... Receiving circuit 20 ... Demodulator 21 ... Decoding Circuit 22 ... Speaker

Claims (5)

[Claims] An electric field strength measuring means for measuring the electric field strength of a signal to be received, and a control means for controlling the number of times of measuring the electric field strength of a signal from a peripheral base station by the electric field strength measuring means are provided. Wireless terminal. 2. An electric field intensity measuring means for measuring the electric field intensity of a signal to be received, and the number of times of measuring the electric field intensity of a signal from a peripheral base station in accordance with a change state of the electric field intensity measured by the electric field intensity measuring means. And a control means for controlling the operation of the wireless terminal. 3. An electric field intensity measuring means for measuring an electric field intensity of a signal to be received, and a detecting means for detecting that the electric field intensity measured by the electric field intensity measuring means has dropped below a predetermined level or changed above a predetermined level. And a control means for controlling the number of times of measurement of the electric field strength of a signal from a peripheral base station according to a detection result of the detection means. 4. An electric field intensity measuring means for measuring an electric field intensity of a signal to be received, a fluctuation amount detecting means for detecting a temporal fluctuation amount of the electric field intensity measured by the electric field intensity measuring means, and a fluctuation amount detecting means. Control means for controlling the number of times of measurement of the electric field strength of a signal from a peripheral base station in accordance with the amount of variation detected in (1). 5. A receiving quality measuring means for measuring the receiving quality of a signal to be received, and measuring the receiving quality of a signal from a peripheral base station when the measuring quality determines that the receiving quality is equal to or higher than a predetermined value. A wireless terminal comprising: control means for controlling the number of times.