JP2006319896A - Radio device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a radio device which selects a best frequency signal at all the time and shortens a demodulation disabled time. <P>SOLUTION: A frequency signal from a base station received by an antenna 2 is amplified by a radio section 8. The amplified frequency signal is demodulated by a transmission/reception control section 9 and that information is output to a display section 12, a voice input/output section 7 and the like. In an auxiliary storage device 10, a memory section 13 for list creation is secured as an area for recording a signal list created by the transmission/reception control section 9. The transmission/reception control section 9 measures an electric field strength of a frequency signal from each of base stations and measures an error rate by demodulating the frequency signal and if the error rate is a predetermined threshold or more, the frequency signal is stored on the signal list as a signal candidate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to frequency selection of a received radio wave that is performed when the received radio wave of a wireless device is deteriorated.

  In a wireless device that is a conventional mobile terminal, the wireless device monitors the quality of the wireless line based on the electric field strength of the frequency signal from the base station and the error rate of the demodulated signal. The service area of each base station overlaps in the same zone, and the base station of the service area with the strongest electric field strength is selected to capture the frequency signal.

  When the wireless device moves through the zone, the electric field strength of the frequency signal from the current base station and the error rate of the demodulated signal decrease. In this case, using the empty time slot, the wireless device itself captures a frequency signal from a base station in a service area having a higher electric field strength among a plurality of service areas, and sequentially acquires the frequency signal and the electric field strength being acquired. There is provided a mobile communication method for selecting a frequency signal having the strongest electric field strength (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 9-327056

  Since the conventional radio apparatus is configured as described above, when signal quality degradation occurs during zone movement, the electric field strength of the frequency signal corresponding to the zone is measured, and the frequency signal being captured is detected. Comparison was made with the electric field strength. Therefore, if the supplemental frequency signal is affected by interference waves, etc., and the electrolysis strength is sufficient, but the signal quality is poor, a new comparison of the field strength between the supplemented frequency signal and another frequency signal is performed. Had to do. Alternatively, there are cases where the frequency signals are not synchronized and cannot be captured. As a result, there is a problem that a long non-demodulable time exists and signal reception cannot be performed smoothly.

  The present invention has been made to solve the above problems, and in addition to measuring the electric field strength of the frequency signal from each base station corresponding to the zone, by measuring the error rate of the demodulated signal, An object of the present invention is to obtain a radio apparatus that always selects the best frequency signal and shortens the non-demodulation time.

The radio apparatus according to the present invention measures the electric field strength of the frequency signal from each base station, demodulates the frequency signal to measure the error rate, and the error rate is equal to or higher than a predetermined threshold. Includes a transmission / reception control unit that creates a signal list using the frequency signal as a signal candidate, and an auxiliary storage device that stores the signal list.
The transmission / reception control unit selects the signal candidate from the signal list and captures the corresponding frequency signal.

  According to the present invention, frequency signals of a certain quality or higher are stored in advance as a signal list, and when electric field deterioration occurs, the best signal candidate is selected and supplemented from the signal list, so that it is necessary to capture another frequency signal. Time is shortened. As a result, it is possible to shorten the demodulation impossible time.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below. 1 is a configuration diagram of a radio apparatus according to Embodiment 1 of the present invention. As shown in FIG. 1, a radio 1 includes an antenna 2 that transmits and receives radio signals to and from a base station, a radio unit 3 that amplifies radio signals, and a transmission control unit (CPU) 4 that modulates and demodulates radio signals. , An auxiliary storage device 5 for storing information, a voice input / output unit 7 and a display unit 8 are provided.

  Next, the operation will be described. The frequency signal from the base station received by the antenna 2 is amplified by the radio unit 8. The amplified frequency signal is demodulated by the transmission / reception control unit 9 and the information is output to the display unit 12 and the voice input / output unit 7. The auxiliary storage device 10 has a list creation memory unit 13 as an area for recording a signal list created by the transmission / reception control unit 9. On the other hand, when transmitting, the audio input to the audio input / output unit 7 is modulated by the transmission / reception control unit 9, amplified by the radio unit 8, and transmitted from the antenna 2.

  FIG. 2 is a diagram illustrating a pilot signal transmitted from the base station to the radio apparatus of FIG. 1 when there is no call. As shown in FIG. 2, a fixed pattern 10 and a fixed pattern for synchronization 11 are embedded in an information signal 12 in a pilot signal 9 transmitted from a base station radio when there is no call.

  FIG. 3 is a flowchart showing the operation of radio apparatus 1 of FIG. 1 in Embodiment 1 of the present invention. It is assumed that the transmission / reception control unit 4 performs the processing flow of FIG. In FIG. 3, first, it is assumed that the wireless device 1 is in a standby state (step ST301).

  In a standby state, when a time during which no signal is transmitted / received (hereinafter referred to as an empty time slot) occurs (step ST302), the wireless device 1 measures the electric field strength of the frequency signal from each base station corresponding to the zone. (Step ST303).

  At that time, each frequency signal is demodulated into a demodulated signal. Then, the error rate of the demodulated signal is measured using the fixed pattern 10 of FIG. 2, and the quality is determined (step ST304). The error rate is “BER (Bit Error Rate) = number of error bits / number of transmission bits”.

  In step ST304, if the error rate of the demodulated signal is greater than or equal to a predetermined threshold, it is determined that the signal is good, and the corresponding frequency signal is stored as a signal candidate in the signal list (the list creation memory unit 6 in FIG. 1) ( Step ST305). On the other hand, if the error rate is less than or equal to the threshold value, it is determined that the error is bad and the signal list is not stored. Then, returning to step ST304, the error rate of the demodulated signal is similarly measured and determined for another frequency signal.

  In the signal list, the signal candidates are sorted in ascending or descending order according to the strength of the electric field strength measured in step ST303 (step ST306).

  When electric field degradation occurs in the frequency signal from the currently used base station (step ST307), the signal candidate having the strongest electric field strength is selected from the signal candidates stored in the signal list, and Acquisition of the frequency signal from the base station to be started is started (step ST308).

  The quality of the acquired frequency signal is determined (step ST309), and if the quality is good, the acquisition is completed (step ST310). Finally, the wireless device 1 enters a standby state again (step ST311). On the other hand, if the quality is poor, the process returns to step ST308, and the same processing is performed for the signal candidate having the next electric field strength. The determination of the quality of the supplemented frequency signal is performed by measuring the error rate of the demodulated signal, as in step ST304.

  In FIG. 3, the time between step ST307 and step ST310 is a non-demodulable time 13, and the other time is a demodulatable time 14. By storing frequency signals with good electric field strength and quality in the signal list in advance as signal candidates, it is possible to shorten the time required to capture a new frequency signal when electric field deterioration occurs. As a result, the demodulation impossible time 13 can be shortened.

  According to the first embodiment, frequency signals of a certain quality or higher are stored in the signal list as signal candidates in advance, and when the electric field deterioration occurs, the best signal candidate is selected from the signal list and supplemented. The time required to capture is reduced. As a result, it is possible to shorten the demodulation impossible time.

Embodiment 2. FIG.
The second embodiment of the present invention will be described below. The radio apparatus according to the second embodiment has the same configuration as that of the radio apparatus according to the first embodiment (the radio apparatus 1 in FIG. 1), and thus description thereof is omitted. Similarly to the first embodiment, it is assumed that pilot signal 9 of FIG. 2 is transmitted from the base station radio when there is no call.

  Next, the operation will be described. Regarding the operation of each component, only the parts different from the first embodiment will be described. FIG. 4 is a flowchart showing the operation of radio apparatus 1 of FIG. 1 in Embodiment 2 of the present invention. It is assumed that the transmission / reception control unit 4 performs the processing flow of FIG. In FIG. 4, first, it is assumed that the wireless device 1 is in a standby state (step ST401).

  In the standby state, when an empty time slot occurs (step ST402), the wireless device 1 measures the electric field strength of the frequency signal from each base station corresponding to the zone (step ST403).

  Each frequency signal is stored as a signal candidate in the signal list (list creation memory unit 6 in FIG. 1) (step ST404).

  In the signal list, the signal candidates are sorted in ascending or descending order according to the strength of the electric field intensity measured in step ST403 (step ST405).

  A frequency signal corresponding to a signal candidate in the signal list is demodulated to obtain a demodulated signal. Then, the error rate of the demodulated signal is measured using the fixed pattern 10 of FIG. 2, and the quality is determined (step ST406). The error rate is “BER = number of error bits / number of transmission bits”.

  If the error rate is poor in step ST406, the corresponding signal candidate in the signal list is deleted or its rank is lowered (step ST407). On the other hand, if the error rate is good, the process returns to step ST406, and the error rate is measured and determined in the same manner for another signal candidate in the signal list. When determining the error rate, a comparison with a threshold value may be performed as in the first embodiment.

  When electric field deterioration occurs in the frequency signal from the currently used base station (step ST408), the signal candidate having the strongest electric field strength is selected from the signal candidates stored in the signal list, and the corresponding signal is selected. Acquisition of the frequency signal from the base station is started (step ST409).

  The quality of the acquired frequency signal is determined (step ST410), and if the quality is good, the acquisition is completed (step ST411). Finally, the wireless device enters a standby state again (step ST412). On the other hand, if the quality is poor, the process returns to step ST409, and the same processing is performed on the signal candidates of the next rank in the signal list. The determination of the quality of the supplemented frequency signal is performed by measuring the error rate of the demodulated signal as in step ST406.

  In FIG. 4, the period between step ST <b> 408 and step ST <b> 411 is a non-demodulable time 17, and the other time is a demodulable time 16. By storing frequency signals with good electric field strength and quality in the signal list in advance as signal candidates, it is possible to shorten the time required to capture a new frequency signal when electric field deterioration occurs. As a result, the demodulation impossible time 17 can be shortened.

  According to the second embodiment, frequency signals of a certain quality or higher are stored in the signal list as signal candidates in advance, and the best signal candidate is selected and supplemented from the signal list when electric field degradation occurs. The time required to capture is reduced. As a result, it is possible to shorten the demodulation impossible time.

It is a block diagram of the radio | wireless apparatus which concerns on Embodiment 1 of this invention. In Embodiment 1 of this invention, it is a figure which shows the pilot signal transmitted with respect to the radio | wireless apparatus of FIG. 1 from a base station at the time of a no-call. 3 is a flowchart showing the operation of the wireless device 1 of FIG. 1 in Embodiment 1 of the present invention. 6 is a flowchart showing the operation of the wireless device 1 of FIG. 1 in Embodiment 2 of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Radio | wireless apparatus, 2 Antenna, 3 Radio | wireless part, 4 Transmission / reception control part (CPU), 5 Auxiliary storage device, 6 Memory | storage part for list creation, 7 Voice input / output part, 8 Display part, 9 Pilot signal, 10 Fixed pattern, 11 Fixed pattern for synchronization, 12 information signal, 13 demodulatable time, 14 demodulatable time, 15 demodulatable time, 16 demodulatable time, 17 demodulatable time, 18 demodulatable time.

Claims (7)

Measure the electric field strength of the frequency signal from each base station, measure the error rate by demodulating the frequency signal, and if the error rate is greater than or equal to a predetermined threshold, select the frequency signal as a signal candidate A transmission / reception control unit for creating a signal list,
An auxiliary storage device for storing the signal list;
The radio apparatus, wherein the transmission / reception control unit selects the signal candidate from the signal list and captures the corresponding frequency signal.   The radio apparatus according to claim 1, wherein the transmission / reception control unit ranks the signal candidates in the signal list based on the electric field strength.   The transmission / reception control unit allocates a pilot signal included in the frequency signal to an empty time slot of the wireless device, and measures the error rate based on a fixed pattern embedded in the pilot signal. 2. The wireless device according to 2. A transmission / reception control unit that measures the electric field strength of the frequency signal from each base station and creates a signal list in which the frequency signals are ranked as signal candidates based on the electric field strength;
An auxiliary storage device for storing the signal list;
The radio apparatus, wherein the transmission / reception control unit selects the signal candidate from the signal list and captures the corresponding frequency signal.   5. The transmission / reception control unit demodulates the frequency signal corresponding to the signal candidate to measure an error rate, and performs ranking in the signal list based on the error rate. The wireless device described.   The radio apparatus according to claim 5, wherein when the error rate is equal to or less than a threshold, the corresponding signal candidate is deleted from the signal list.   The transmission / reception control unit allocates a pilot signal included in the frequency signal to an empty time slot of the wireless device, and measures the error rate based on a fixed pattern embedded in the pilot signal. The wireless device according to claim 5 or 6.

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