JP2002246969A - Diversity receiver, diversity receiving method and diversity control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce processing loads, without degrading reception characteristics, and to reduce power consumption in diversity control. SOLUTION: An antenna changeover 203 fetches reception signals from an antenna element 201 and an antenna element 202 respectively. An antenna changeover control unit 206 controls the antenna changeover 203, so as to fetch the reception signals from the antenna element, for which the measured result of a reception level is the highest in a reception slot section. An antenna changeover management part 208 monitors the fluctuation amount of phasing, and stops the changeover of the antenna element in the antenna changeover 203, corresponding to the fluctuation amount of phasing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to diversity control used in a TDMA mobile unit represented by a PDC (Personal Digital Cellular) digital mobile phone, and more particularly to antenna switching according to the communication state of the mobile unit. The present invention relates to diversity control for performing control.

[0002]

2. Description of the Related Art TDMA (Time Divisional Multiple A)
Diversity control is widely used in mobiles that perform communication according to the ccess) method in order to reduce deterioration in reception quality due to fading. The TDMA system is a well-known multiple access system, in which a single carrier is divided into a plurality of time sections (slots), and a channel of each user is assigned to the divided slot, whereby a plurality of users are assigned to a single carrier. It is a method to accommodate. Diversity control is a technique for receiving a plurality of signals having low fading correlations from a diversity antenna composed of a plurality of antenna elements and appropriately using the received signals to reduce a drop in a reception level due to fading.

In conventional mobile communication using diversity control, an idle section in which a desired signal is not received is provided between a transmission slot and a reception slot in a frame. The mobile measures the reception level of the reception signal fetched from each antenna element during this idle period, and can prevent a drop in the reception level by selecting the antenna element having the highest reception level.

[0004]

However, in the above-mentioned conventional diversity control, since the reception level is measured even when there is no need to switch the antenna element, there is a problem that the power consumption increases.

[0005] The present invention has been made in view of the above viewpoints, and it is an object of the present invention to provide a diversity receiving apparatus capable of reducing a processing load without deteriorating reception characteristics and reducing power consumption.

[0006]

SUMMARY OF THE INVENTION A diversity receiving apparatus according to the present invention comprises: a diversity antenna comprising a plurality of antenna elements; and an antenna switching means for switching between the plurality of antenna elements and taking in a received signal from a switching destination antenna element. And a monitoring means for monitoring the amount of fading fluctuation, and an adaptive control means for stopping the switching of antenna elements in the antenna switching means in accordance with the monitored amount of fading fluctuation.

According to this configuration, the switching of the antenna elements is stopped in accordance with the amount of fluctuation of the fading. Therefore, for example, when the amount of fluctuation of the fading is small, the switching of the antenna elements is stopped to perform the diversity control. And good reception quality can be obtained. Therefore, the processing load on the diversity receiving apparatus can be reduced.

In the diversity receiver according to the present invention, in the diversity receiver, measuring means for measuring a reception level in an idle section of the reception signal fetched by the antenna switching means for each antenna element, and measuring the reception level according to the measurement result of the reception level. Means for selecting a target antenna element from a plurality of antenna elements, antenna switching control means for controlling switching of antenna elements in the antenna switching means so as to fetch a received signal from the selected target antenna element, and fetching from the target antenna element. Means for decoding the received signal to obtain received data.

According to this configuration, the antenna element that has fetched the signal with the highest reception level can be selected as the target antenna element, and the received data can be obtained based on the received signal fetched from the target antenna element. And
When the fading fluctuation is stable, by stopping the switching of the antenna elements, the signal is continuously taken in from the antenna element having the highest reception level. High reception quality can be obtained. As a result, the processing load on the diversity receiver can be reduced.

The diversity receiving apparatus according to the present invention, in the diversity receiving apparatus, employs a configuration in which the antenna switching means discards a signal included in an idle section when the switching of the target antenna element is stopped by the adaptive control means. .

According to this configuration, when the switching of the target antenna element is stopped, the received signal included in the idle section is discarded. Thus, for example, when the amount of fluctuation in fading is small, the switching of the target antenna element is not performed, so that the processing accompanying the diversity control can be omitted, and the power consumption can be reduced. Specifically, the power consumption can be reduced by discarding the reception signal in the idle section in the antenna switching unit and omitting the wireless reception processing in the idle section. That is, since the wireless reception processing is performed only in the section other than the idle section, the power consumption is reduced by the power consumed in the wireless reception processing in the idle section as compared with the case where the conventional diversity control is performed.

A diversity receiving apparatus according to the present invention, in the diversity receiving apparatus described above, further comprises a storage unit for storing an antenna identification signal for identifying a target antenna element to be switched over over a plurality of unit control lengths, and the monitoring unit includes: A configuration is employed in which the amount of fading variation is monitored based on the antenna identification signal stored in the storage means.

According to this configuration, when the same antenna element is continuously selected a predetermined number of times or more, it is determined that the fading fluctuation is stable, and the switching of the target antenna element can be stopped. Power can be reduced.

[0014] In the diversity receiver according to the present invention, in the diversity receiver described above, the measuring means measures a reception level of a reception signal fetched from the target antenna element.
The monitoring means monitors the amount of fluctuation of fading on the basis of the antenna identification signal and the fluctuation amount of the reception level measured by the measuring means between the unit control lengths.

According to this configuration, the amount of fading fluctuation is monitored based on the amount of fluctuation of the reception level, and the switching of the target antenna element is stopped according to the monitoring result.
Power consumption can be reduced.

A communication terminal device according to the present invention employs a configuration including the diversity receiving device. According to this configuration, it is possible to reduce the power consumption of the communication terminal device. A base station apparatus according to the present invention employs a configuration including the diversity receiving apparatus. According to this configuration, it is possible to reduce power consumption in the base station device.

According to the diversity receiving method of the present invention, an antenna switching step of switching a plurality of antenna elements to receive a reception signal from a switching destination antenna element, and a reception level in an idle section of the reception signal fetched from the plurality of antenna elements. A measuring step of measuring for each antenna element, a selecting step of selecting a target antenna element from the plurality of antenna elements according to the measurement result of the reception level, and an antenna element to fetch a received signal from the selected target antenna element An antenna switching control step of controlling switching, a step of decoding a received signal taken from a target antenna element to obtain received data, a monitoring step of monitoring a fading variation, and an antenna according to the monitored fading variation. Stop switching the target antenna element in the switching process And 応制 your process, so as to include a.

According to this method, the switching of the antenna elements is stopped in accordance with the amount of fluctuation of fading. For example, when the amount of fluctuation of fading is small, the switching of the antenna elements is stopped to perform diversity control. And good reception quality can be obtained. Therefore, the processing load on the diversity receiving apparatus can be reduced, and the power consumption can be reduced.

The diversity control program according to the present invention comprises:
A computer, an antenna switching means for switching a plurality of antenna elements and receiving a received signal from a switching destination antenna element, a monitoring means for monitoring a variation in fading,
An adaptive control means for stopping switching of the antenna element according to the monitored fading variation is employed.

According to this configuration, the switching of the antenna elements is stopped in accordance with the amount of fluctuation of fading. For example, when the amount of fluctuation of fading is small, the switching of antenna elements is stopped to perform diversity control. And good reception quality can be obtained. Therefore, the processing load on the diversity receiving apparatus can be reduced, and the power consumption can be reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventor has paid attention to the fact that a stable communication environment can be obtained even in mobile communication depending on the use condition of a mobile such as when a user stops and performs communication. In the communication environment described above, the present inventors have found that it is possible to maintain a good reception quality while reducing the control amount by fixing and using the once selected antenna element without switching, and have arrived at the present invention.

In other words, the gist of the present invention is to monitor the amount of fading variation in the diversity receiving apparatus and, if the amount of fading variation is smaller than a predetermined amount, continue to select the antenna element once selected. is there.

(Embodiment) FIG. 1 is a schematic diagram showing a configuration of a wireless communication system according to an embodiment of the present invention.
The transmitting device 101 and the receiving devices 111, 112, and 113 are connected by a wireless line, and a signal transmitted from the transmitting device 101 is transmitted by the wireless line. Transmission device 1
No. 01 divides a transmission wave into a plurality of time sections (slots), allocates a channel of each receiving apparatus to the divided slots, and performs transmission. Here, channel 1 (Ch1) is set to receiving device 111, and channel 2 (C1) is set to receiving device 112.
h2), the channel 3 (Ch3) is allocated to the receiving device 113. Receiving devices 111, 112, 113
Extracts the signal of the channel assigned to each device, performs radio reception processing, decoding processing, and the like on the extracted signal to obtain desired reception data.

Receiving apparatus 111 has two antenna elements, and performs diversity reception by appropriately switching these antenna elements. In this sense, the reception device 111 may be referred to as the diversity reception device 111 in this specification. Diversity receiving apparatus 111 performs antenna switching control, that is, diversity control, for each unit control length. In the present embodiment, a case will be described as an example where diversity control is performed for each frame. An antenna used for diversity reception is generally composed of a plurality of antenna elements and is called a diversity antenna. Each antenna element constituting the diversity antenna may be called a diversity branch.

FIG. 3 shows the transmitting device 101 and the receiving device 11
2 shows a time chart of signals transmitted to and received from the communication device 1;
3A illustrates a frame configuration of a signal transmitted by the transmission device 101, FIG. 3B illustrates a frame configuration of a signal received by the transmission device 101, and FIG. 3C illustrates a configuration of a signal transmitted and received by the diversity reception device 111. 1 shows a frame configuration of a signal to be transmitted.

As shown in FIG. 3A, the transmitting device 101
Allocates signals addressed to the receiving devices 111, 112, and 113 to the transmission slot T1, the transmission slot T2, and the transmission slot T3, respectively, and transmits the signals. Further, as shown in FIG. 3B, the transmitting apparatus 101 includes the receiving apparatuses 111 and 11.
2 and 113 are respectively received by reception slots R1 and R1.
The reception is performed in the reception slot R2 and the reception slot R3.

The receiving apparatus 111 transmits and receives signals with the time allocation shown in FIG. That is, the frame used by the receiving apparatus 111 for communication includes a receiving slot section for receiving a desired signal, a peripheral level detecting section for receiving a signal transmitted from another transmitting apparatus, and a transmitting slot for transmitting a signal to the transmitting apparatus 101. And a section.

Receiving device (diversity receiving device) 111
Extracts the signal assigned to the transmission slot T1 from the transmission signal of the transmission apparatus 101 in the reception slot section to obtain reception data. Further, receiving apparatus 111 transmits a signal to transmitting apparatus 101 in a transmission slot section. Further, an idle section (an idle section is, for example, a section corresponding to 5% of one frame length in the case of the PDC full rate system) at the head of the frame, and a diversity antenna is formed in the idle section. Switching control of antenna elements, that is, diversity control is performed.

In this embodiment, a case will be described in which diversity receiving apparatus 111 includes two antenna elements (diversity branches). However, the present invention is not limited to this, and a plurality of antennas capable of diversity reception are provided. What is necessary is just to provide an element.

FIG. 2 is a block diagram showing the internal configuration of diversity receiving apparatus 111 shown in FIG. In this figure, in a reception slot section, antenna switching section 203 switches antenna elements under the control of antenna switching control section 206, and takes in a received signal from the switching destination antenna element. Also, the antenna switching unit 203
In the idle period, the antenna element 201 and the antenna element 202 are alternately switched, a received signal is fetched from each antenna element, and the fetched signal is output to the RF unit 204. Further, when the switching of antenna elements is stopped in adaptive control section 211 described later, antenna switching section 203 discards the received signal in the idle section. Here, the antenna element 201
The antenna element 202 is a diversity branch used for diversity reception.

[0031] RF section 204 performs predetermined radio reception processing on the reception signal output from antenna switching section 203. That is, the RF unit 204 converts the frequency of the received signal from the high frequency band to the intermediate frequency band, and performs processing such as limiter amplification and quadrature detection on the received signal converted to the intermediate frequency band.
The RF unit 204 converts a signal included in a reception slot section out of the reception signals subjected to the radio reception processing into the reception level measurement unit 2.
05 and the decoding unit 212. Also, the RF unit 204
Performs wireless reception processing on the received signals in the idle section taken in from the antenna element 201 and the antenna element 202, and outputs the signals subjected to the wireless reception processing to the reception level measurement unit 205, respectively.

[0032] Decoding section 212 decodes the received signal output from RF section 204 to obtain received data. Reception level measurement section 205 measures the reception level of the reception signal output from RF section 204 for each antenna element, and outputs the measurement result to comparison section 213 and monitoring section 210. As the reception level, for example, RSSI (Received Signal Strength)
Indicator: received signal strength). Comparison section 213
Compares the reception levels output from the reception level measurement unit 205 and selects the antenna element having the highest reception level as the target antenna element.

The timing control section 207 outputs a timing signal to the antenna switching control section 206 in an idle section of each slot. The antenna switching control unit 206 includes:
The comparison unit 213 is monitored, and when a timing signal is input (that is, when processing in an idle section in a frame is being performed), the reception unit 213 switches to the target antenna element selected by the comparison unit 213 and takes in a reception signal. The antenna switching unit 203 is controlled as described above. Further, when the switching of the antenna element in the antenna switching unit 203 is stopped by the adaptive control unit 211 described later, the comparison unit 213 does not select the target antenna element. 209,
The antenna switching unit 203 switches to the target antenna element selected in the previous frame and takes in the received signal.
Control. Further, antenna switching control section 206 outputs an antenna identification signal for identifying the antenna element selected by comparing section 213 to memory 209. Here, it is assumed that the antenna identification signal A1 is output when the antenna element 201 is selected, and the antenna identification signal A2 is output when the antenna element 202 is selected.

The antenna switching management unit 208 includes a memory 209 for holding an antenna identification signal and a reception level measurement unit 2
The monitoring unit 210 that monitors the amount of fading variation based on the reception level measured at 05 and the antenna identification signal held in the memory 209, and adaptively controls the antenna switching unit 203 according to the amount of fading variation. And an adaptive control unit 211.

The monitoring unit 210 refers to the antenna identification signal held in the memory 209 and determines whether the same antenna element is continuously selected for a predetermined frame (that is, whether the antenna identification signal A1 or the antenna identification signal A
2 is continuously monitored for a predetermined frame). Further, the monitoring unit 210 is provided with the reception level measurement unit 2
It monitors whether the measurement result of the reception level at 05 is larger than a predetermined reference value. The adaptive control unit 211 controls the stop of the switching of the target antenna element in the antenna switching unit 203 and the release of the stop of the switching based on the monitoring result of the fluctuation amount of the fading by the monitoring unit 210.

Next, the diversity receiving apparatus 1 having the above configuration
The operation of No. 11 will be described. FIG. 4 is a flowchart showing the operation of the diversity receiving apparatus 111 for one slot. In FIG. 4, the processing in steps (hereinafter abbreviated as “ST”) 401 to ST407 and ST413 is performed in an idle section, and ST408 to ST412 are performed.
Is performed in the reception slot section.

First, in ST401, the antenna switching unit 2
03, the antenna element 201 and the antenna element 2
From 02, the signal of the idle section is taken in. Then
In ST402, if the antenna switching in the antenna switching unit 203 has been stopped by the control of the adaptive control unit 211, the process proceeds to ST403. On the other hand, if the antenna switching has not been stopped and the stop of the switching has been released, Then, the received signals fetched from each antenna element are output to RF section 204, and the process proceeds to ST404.

In ST 403, the received signal in the idle section is discarded in antenna switching section 203. Next, in ST413, antenna switching control section 206 controls antenna switching section 203 to switch to the target antenna element selected in the previous frame and take in the received signal.

In ST404, the RF unit 204
A predetermined wireless reception process is performed on each of the signals in the idle section received from antenna element 201 and antenna element 202. Next, in ST405, reception level measurement section 205 measures the reception level of each reception signal after the wireless reception processing. Next, in ST406, comparing section 213 compares the reception level for each antenna element, and as a result of the comparison, selects the antenna element that has received the received signal with the highest reception level as the target antenna element. Next, in ST407, the antenna switching control unit 206
Control is performed such that a signal in the reception slot section is taken in from the selected target antenna element.

In ST408, antenna switching section 203 fetches a signal in the reception slot section from the target antenna element selected in comparison section 213 under the control of antenna switching control section 206. Next, ST4
In step 09, the RF unit 204 performs a predetermined radio reception process on the reception signal in the reception slot section taken in from the target antenna element. Next, ST41
If the value is 0, the decoding unit 212 performs a predetermined decoding process on the reception signal in the reception slot section after the radio processing, and obtains reception data.

In ST411, reception level measuring section 205
In, the reception level in the reception slot section is measured. Next, in ST412, the antenna switching management unit 208 performs control of stopping or canceling the antenna switching in the antenna switching unit 203. Specifically, when the same antenna element is continuously selected a predetermined number of times or more, control for stopping the switching of the antenna element is performed. Further, in a state where the switching of the antenna elements is stopped, if the reception level in the reception slot section is higher than a predetermined reference value, control for canceling the stop of the switching is performed.

As described above, after the control of the switching stop or the switching cancellation is performed, the detection of the peripheral level and the transmission of the signal are performed, and the processing of one slot is completed. Then, reception of a signal in an idle section in the next frame is started.

As described above, according to the present embodiment, when the amount of fading fluctuation monitored by monitoring section 210 is small, adaptive control section 211 sets antenna switching section 20
The switching in 3 is stopped. Accordingly, when the amount of fluctuation in fading is small, good reception quality can be obtained without performing diversity control, and the processing load on the diversity receiving apparatus can be reduced.

Further, in the diversity receiving apparatus according to the present embodiment, adaptive control section 211 controls antenna switching section 203 to stop the switching of the target antenna element when the amount of fading fluctuation is smaller than a predetermined amount, and to control the idle state. The received signal included in the section is discarded. This allows
By fixing the target antenna element and not performing diversity control when the amount of fluctuation of fading is small,
The power consumption can be reduced by omitting the processing associated with the diversity control. Specifically, when the amount of fluctuation of fading is small, the received signal in the idle section is discarded in antenna switching section 203, and the wireless reception processing in the idle section is omitted, so that the power consumption accompanying the wireless reception processing is reduced. Is done. That is, in the present embodiment, when fading fluctuation is stable, RF section 204 performs radio reception processing only in a section other than the idle section, and thus the power consumption consumed in the radio reception processing in the idle section. The power consumption is reduced as compared with the conventional diversity control.

The diversity receiver 111 according to the present embodiment is used for a mobile phone or a PDA (Personal Digital Assis
tant :) and so on. In particular, diversity receiving apparatus 111 according to the present embodiment is mounted on a mobile body that freely moves within a cell in a cellular system. By mounting the diversity receiving apparatus according to the present embodiment on such a communication terminal apparatus, power consumption of the communication terminal apparatus can be reduced.

The moving body does not always move, but may be used in a stationary state or may be used by moving at a speed about the walking speed of a human depending on the use condition of the user. In such a case, it is considered that the fluctuation of the fading is stable unless there is a special situation such as shadowing. Therefore, when the diversity receiving apparatus according to the present embodiment is used in a stationary state or used during low-speed movement, switching of antenna elements can be stopped to reduce power consumption.

Further, by mounting diversity receiving apparatus 111 according to the present embodiment in a base station apparatus of a cellular system, power consumption in the base station apparatus is reduced.

As will be apparent to those skilled in the art, the present invention can be implemented using a general commercially available digital computer and microprocessor incorporating a program for causing the technology described in the above embodiment to function. Can be done. Further, as will be apparent to those skilled in the art, the present invention includes a computer program created by those skilled in the art based on the technology described in the above embodiment.

The scope of the present invention includes a computer program product that is a computer-readable recording medium on which a program for causing the technology described in the above embodiment to function is recorded. This recording medium is a disk such as a floppy (registered trademark) disk, an optical disk, a CDROM and a magnetic disk, a ROM, a RAM, an EPRO, and the like.
M, EEPROM, magneto-optical card, memory card, DVD, or the like, but is not limited thereto.

In the present embodiment, when the same antenna element is continuously selected as a target antenna element for a predetermined number of times or more, it is determined that the amount of change in fading is small. However, the present invention is not limited to this. GPS (Global Pos
It is also possible to detect the moving speed of the receiving apparatus by using a directional system and determine that the amount of fluctuation of fading is small when the detected moving speed is lower than a predetermined reference speed.

[0051]

As described above, according to the present invention,
Since the switching of the antenna elements constituting the diversity antenna is stopped according to the amount of fading variation, for example, by stopping the switching of the antenna elements when the amount of fading variation is small, good reception without performing diversity control is achieved. Quality can be obtained. Therefore, the processing load on the diversity receiving apparatus can be reduced, and the power consumption can be reduced.

When the switching of the target antenna element is stopped, the received signal included in the idle section is discarded. As a result, the wireless reception processing is performed only in a section other than the idle section, so that the power consumption is reduced by the power consumed in the wireless reception processing in the idle section as compared with the case where the conventional diversity control is performed. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a wireless communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of a receiving device according to an embodiment of the present invention.

FIG. 3 is a diagram showing a relationship between a transmission signal and a reception signal in TDMA.

FIG. 4 is a flowchart showing an operation for one slot of the diversity receiver according to one embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 101 transmission device 111 diversity receiving device 201, 202 antenna element 203 antenna switching unit 204 RF unit 205 reception level measuring unit 206 antenna switching control unit 208 antenna switching management unit 209 memory 210 monitoring unit 211 adaptive control unit 213 comparison unit

Claims (9)

[Claims] 1. A diversity antenna comprising a plurality of antenna elements, an antenna switching means for switching between the plurality of antenna elements and taking in a received signal from a switching destination antenna element, and a monitoring means for monitoring a fading fluctuation amount. And a adaptive control means for stopping the switching of the antenna element in the antenna switching means in accordance with the monitored fading variation. 2. A measuring means for measuring, for each antenna element, a reception level of a received signal fetched by an antenna switching means in an idle section, and a target antenna element is selected from a plurality of antenna elements according to a result of measuring the reception level. Means, antenna switching control means for controlling switching of the antenna element in the antenna switching means so as to take in a received signal from the selected target antenna element, and means for obtaining received data by decoding the received signal taken from the target antenna element The diversity receiver according to claim 1, comprising: 3. The antenna switching means, when the switching of the target antenna element is stopped by the adaptive control means,
3. The diversity receiver according to claim 1, wherein a signal included in an idle section is discarded. 4. A storage unit for storing an antenna identification signal for identifying a target antenna element to be switched over a plurality of unit control lengths, wherein the monitoring unit stores the antenna identification signal stored in the storage unit. The amount of fluctuation of fading is monitored on the basis of the information.
The diversity receiver according to any one of the above. 5. A measuring means for measuring a reception level of a reception signal fetched from a target antenna element, and a monitoring means for measuring an antenna identification signal and an amount of fluctuation between the unit control lengths of the reception level measured by said measurement means. The diversity receiver according to any one of claims 2 to 4, wherein the amount of change in fading is monitored based on the received signal. 6. A communication terminal device comprising the diversity receiving device according to claim 1. Description: 7. A base station apparatus comprising the diversity receiver according to any one of claims 1 to 5. 8. An antenna switching step of switching a plurality of antenna elements to receive a reception signal from a switching destination antenna element, and measuring a reception level in an idle section of the reception signal fetched from the plurality of antenna elements for each antenna element. Measurement step, a selection step of selecting a target antenna element from the plurality of antenna elements according to a measurement result of a reception level, and antenna switching controlling switching of the antenna element so as to take in a reception signal from the selected target antenna element. A control step, a step of decoding a received signal taken from the target antenna element to obtain reception data, a monitoring step of monitoring a variation of fading, and a target antenna element in an antenna switching step according to the monitored variation of fading. And an adaptive control step of stopping the switching of Characteristic diversity receiving method. 9. A computer, comprising: an antenna switching means for switching a plurality of antenna elements to receive a received signal from a switching destination antenna element; a monitoring means for monitoring a fading variation; an antenna element according to the monitored fading variation; A diversity control program for functioning as an adaptive control means for stopping the switching of switches.