JP2022043858A - Base station device, mobile station device, and wireless communication system - Google Patents

Abstract

To reduce the occurrence of a reception error associated with switching a transmission source of a DL signal.SOLUTION: A base station device 20 according to the present invention includes a transmission parameter determination unit 227 that determines a transmission parameter related to UL signal transmission, a DL signal transmission source determination unit 114 that determines one base station transmission/reception device 21 for transmitting a DL signal including the transmission parameter from a plurality of base station transmission/reception devices 21, a DL switching notification generation unit 226 that generates a switching notification that notifies the switching of the base station transmission/reception device 21 that transmits the DL signal to the mobile station device 10, and a DL signal transmission source selection unit 229 that includes the switching notification in the DL signal, transmits the signal to the mobile station device 10 via the first base station transmission/reception device 21, and then switches the base station transmission/reception device 21 that transmits the DL signal at a predetermined timing to the second base station transmission/reception device 21 when the base station transmission/reception device 21 that transmits the DL signal is switched from the first base station transmission/reception device 21 to the second base station transmission/reception device 21.SELECTED DRAWING: Figure 2

Description

The present invention relates to base station equipment, mobile station equipment and wireless communication systems.

The FPU (Field Pickup Unit), which is a wireless transmission device for transmitting program material, has become important as a device for relaying a program or transmitting an interviewed video to a broadcasting station. In particular, in relaying programs such as relay road races and marathons, the FPU is indispensable for transmitting video and audio from a moving relay vehicle.

In recent years, TDD-SVD-MIMO (Time Division Duplex-Singular Value Decomposition-Multiple-Input Multiple-Output) method has been studied as a transmission method in FPU (see, for example, Patent Document 1 and Non-Patent Document 1). .. The TDD-SVD-MIMO system is a system in which transmission parameters related to signal transmission from a mobile station device to a base station device are fed back from the base station device to the mobile station device using time division duplex (TDD). According to this method, it is possible to stably transmit a large amount of program material from a mobile station device (FPU) to a base station device.

Japanese Patent No. 6328021

"Portable quasi-microwave band OFDM digital wireless transmission system for transmission of ultra-high-definition television broadcast program materials", ARIB STD-B75 1.0 version, Association of Radio Industries and Businesses

FIG. 8 is a diagram showing a configuration example of a conventional wireless communication system 1A using the TDD-SVD-MIMO system.

The wireless communication system 1A shown in FIG. 8 includes a mobile station video / audio device 2, a mobile station device 10A, a base station device 20A, and a base station video / audio device 3. The mobile station device 10A and the base station device 20A communicate with each other by the TDD-SVD-MIMO method. Specifically, in one fixed-length frame (TDD frame), the mobile station device 10A transmits a video / audio signal which is a program material to the base station device 20A, and the base station device 20A is the mobile station device. The transmission parameters related to the transmission of the video / audio signal by the 10A are transmitted to the mobile station apparatus 10A. Hereinafter, a line for transmitting a video / audio signal from the mobile station device 10A to the base station device 20A is referred to as an uplink (Up-Link (UL) line). Further, a line for transmitting transmission parameters and the like from the base station device 20A to the mobile station device 10A is referred to as a downlink (Down-Link (DL) line). Further, a signal transmitted via a UL line is referred to as a UL signal, and a signal transmitted via a DL line is referred to as a DL signal.

The mobile station video / audio device 2 includes a camera / microphone for acquiring video / audio signals, an encoder for encoding the acquired video / audio signals, and the like. The mobile station video / audio device 2 encodes the acquired video / audio signal and outputs it to the mobile station device 10A.

As shown in FIG. 8, the mobile station device 10A includes a mobile station modulation / demodulation device 11A and a mobile station transmission / reception device 12. The mobile station modulation / demodulation device 11A modulates the video / audio signal output from the mobile station video / audio device 2 and transmits it as a UL signal to the base station device 20A via the mobile station transmission / reception device 12. Further, the mobile station device 11A demodulates the DL signal received via the mobile station transmission / reception device 12.

As shown in FIG. 8, the base station device 20A includes a plurality of base station transmission / reception devices 21 (base station transmission / reception devices 21-1 to 21-N) and a base station modulation / demodulation device 22A. Each of the plurality of base station transmission / reception devices 21 and the base station modulation / demodulation device 22A are connected via, for example, an optical line.

The plurality of base station transmission / reception devices 21 are installed at different locations. The base station transmission / reception device 21 has a predetermined communication range, and when the mobile station device 10A exists within the communication range, the base station transmission / reception device 21 can communicate with the mobile station device 10A.

The base station modulation / demodulation device 22A demodulates the UL signal received by the base station transmission / reception device 21 to acquire a video / audio signal, and outputs the video / audio signal to the base station video / audio device 3. Further, the base station modulation / demodulation device 22A determines the transmission parameters related to the transmission of the UL signal by the mobile station device 10A, modulates the DL signal including the determined transmission parameters, and is one of the plurality of base station transmission / reception devices 21. Transmission is performed to the mobile station device 10A via the base station transmission / reception device 21.

The base station video / audio device 3 includes a decoder that decodes the video / audio signal output from the base station modulation / demodulation device 22A, a monitor / speaker that reproduces the decoded video / audio signal, and the like.

In the case of a wide range of relays such as marathons and relay road races, a plurality of base station transmission / reception devices 21 are installed, and as the mobile station device 10A moves, the base station transmission / reception device 21 that communicates with the mobile station device 10A is sequentially switched.

FIG. 9 is a diagram for explaining switching of the base station transmission / reception device 21 that communicates with the mobile station device 10A. In FIG. 9, for the sake of simplicity, a case where switching is performed by two adjacent base station transmission / reception devices 21-1, 21-2 will be described as an example.

As described above, the base station transmission / reception devices 21-1, 21-2 each have a predetermined communication range. The communication range of the base station transmission / reception device 21-1 and the communication range of the base station transmission / reception device 21-2 partially overlap, and the overlapping range is referred to as a "switching section".

When the mobile station device 10A moves from the communication range of the base station transmission / reception device 21-1 to the communication range of the base station transmission / reception device 21-2, the DL is shown in FIG. 9 in the switching section where the two communication ranges overlap. The base station transmission / reception device 21 that transmits a signal is switched from the base station transmission / reception device 21-1 to the base station transmission / reception device 21-2. The switching may be performed manually by the operator or automatically performed by the base station modulation / demodulation device 22A.

In the switching section, the UL signal transmitted from the mobile station device 10A can be received by both the base station transmission / reception device 21-1 and the base station transmission / reception device 21-2. The UL signals received by the base station transmission / reception devices 21-1 and 21-2 are aggregated in the base station modulation / demodulation device 22A, and processing such as synthesis is performed.

FIG. 10 is a diagram showing the operations of the base station transmission / reception device 21-1,21-2 and the mobile station device 10A in the above-mentioned switching section in chronological order.

As shown in FIG. 10, in the TDD method, the transmission of the DL signal from the base station transmission / reception device 21 and the transmission of the UL signal from the mobile station device 10A alternate in time in a fixed-length TDD frame. Will be done. Further, the head of the DL signal and the UL signal includes a preamble signal that serves as a mark for detecting the head position of the signal.

When the mobile station device 10A is present in the switching section, the UL signal transmitted from the mobile station device 10A is received by the base station transmission / reception device 21-1 and the base station transmission / reception device 21-2, respectively. At this time, due to the difference in the distance from the mobile station device 10A to the base station transmitter / receiver 21-1,21-2, there is a difference in the time when the UL signal is received by each of the base station transmitter / receiver 21-1,21-2. do. However, the base station modulation / demodulation device 22A can absorb this difference and perform processing such as synthesis.

The DL signal transmitted from one of the base station transmission / reception devices 21 (base station transmission / reception device 21-1 in FIG. 10) among the plurality of base station transmission / reception devices 21 is received by the mobile station device 10A. The mobile station apparatus 10A detects the head of the DL signal using the preamble signal included in the DL signal as a marker. Here, in a radio propagation path in which a large number of reflected waves exist, for example, a preamble signal of a reflected wave having a high arrival level may be erroneously detected as a head position.

The base station transmission / reception device 21 transmits a DL signal at the same timing (for example, at the beginning of the TDD frame) in each TDD frame. That is, the transmission interval of the DL signal is constant. Therefore, the mobile station apparatus 10A predicts the reception time of the next DL signal from the frame length of the predetermined fixed TDD frame after first detecting the head position of the DL signal, and is near the predicted time. Detects the preamble signal. By doing so, the detection accuracy of the head position of the DL signal can be improved.

When the base station transmission / reception device 21 for transmitting the DL signal is switched when predicting the reception time of the DL signal using the frame length of the TDD frame described with reference to FIG. 10, the head position of the DL signal is changed. There is a problem that it may not be detected correctly. Hereinafter, this problem will be described with reference to FIG.

In FIG. 11, in the TDD frame 1 and the TDD frame 2, the DL signal is transmitted by the base station transmission / reception device 21-1, and in the TDD frame 3, the base station transmission / reception device 21 that transmits the DL signal is the base station transmission / reception device 21-. It is assumed that the device is switched from 1 to the base station transmitter / receiver 21-2. Further, in FIG. 11, it is assumed that the base station transmission / reception device 21-1 and the base station transmission / reception device 21-2 transmit a DL signal at the same timing (for example, at the beginning of the TDD frame) in each TDD frame.

As described with reference to FIG. 10, the mobile station apparatus 10A predicts the time when the DL signal is received in the frame 3 based on the time when the DL signal is received in the frame 2 and the frame length of the TDD frame. Here, when the base station transmission / reception device 21-2 is closer to the mobile station device 10A than the base station transmission / reception device 21-1, in the TDD frame 3, from the base station transmission / reception device 21-2, as shown in FIG. The transmitted DL signal reaches the mobile station device 10A earlier than the predicted time. If the difference between the predicted time and the time when the DL signal actually arrives is small, it is possible to detect the beginning of the DL signal. On the other hand, if the difference between the predicted time and the time when the DL signal actually arrives becomes large, the mobile station apparatus 10A cannot correctly detect the head position of the DL signal, and as a result, a reception error occurs. FIG. 11 shows an example in which the DL signal arrives earlier than the predicted time, but similarly, when the DL signal arrives later than the predicted time, the head position of the DL signal can be correctly detected. It may not be possible.

As a method of avoiding the above-mentioned problem, a method of switching the base station transmission / reception device 21 for transmitting a DL signal at a position where the distance between the mobile station device 10A and the base station transmission / reception devices 21-1 and 21-2 are equal is conceivable. However, in this method, the position for switching the base station transmission / reception device 21 for transmitting the DL signal is restricted. Further, it is assumed that the base station transmission / reception device 21 for transmitting the DL signal cannot be switched at the ideal position where the distances between the mobile station device 10A and the base station transmission / reception devices 21-1 and 21-2 are equal. .. For example, at a position where the distances between the mobile station device 10A and the base station transmission / reception devices 21-1 and 21-2 are equal, a shield is provided between the base station transmission / reception device 21-2 and the mobile station device 10A, which are switching destinations. If there is a problem with signal transmission / reception, such as the presence of, switching should not be performed.

An object of the present invention is a base station device, a mobile station device, and a wireless communication system receiving device that can solve the above-mentioned problems and reduce the occurrence of reception errors due to switching of a base station transmitting / receiving device that transmits a DL signal. Is to provide.

In order to solve the above problems, the base station apparatus according to the present invention is a base station apparatus that communicates with a mobile station apparatus by a time-division duplex method via a plurality of base station transmission / reception devices, and is the mobile station apparatus. A base station that transmits a downlink signal including the transmission parameter to the mobile station device from the transmission parameter determination unit that determines the transmission parameter related to the transmission of the uplink signal from the above and the plurality of base station transmission / reception devices. A transmission source determination unit that determines a transmission / reception device, a switching notification generation unit that generates a switching notification that notifies the mobile station device of switching of a base station transmission / reception device that transmits the downlink signal to the mobile station device, and the down. When the base station transmitter / receiver that transmits the link signal to the mobile station apparatus is switched from the first base station transmitter / receiver to the second base station transmitter / receiver, the switching notification is included in the downlink signal and the first Switching to switch the base station transmitter / receiver that transmits the downlink signal to the mobile station apparatus at a predetermined timing to the second base station transmitter / receiver after transmitting to the mobile station apparatus via the base station transmitter / receiver. It has a department.

Further, in the base station apparatus according to the present invention, the offset amount, which is the time difference between the first base station transmitter / receiver and the second base station transmitter / receiver, receives the uplink signal from the mobile station apparatus, is calculated. It is preferable that the switching unit further includes a time difference calculation unit, and the switching unit includes the switching notification and the offset amount in the downlink signal and transmits the switching unit to the mobile station device via the first base station transmitting / receiving device.

Further, the mobile station device according to the present invention is a mobile station device that communicates with a base station device including a plurality of base station transmission / reception devices by a time-division duplex method, and is among the plurality of base station transmission / reception devices. A mobile station transmitter / receiver for receiving a downlink signal, which includes transmission parameters for transmission of an uplink signal from the mobile station apparatus, which is transmitted from one base station transmitter / receiver at the same timing in each fixed-length frame. A head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the downlink signal, a reception time of the head of the downlink signal in the frame, and a frame. A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the frame length is provided, and the head detection unit includes a reception time at the head of the downlink signal by the reception time prediction unit. When is predicted, the head detection process is performed at the timing corresponding to the predicted reception time, and the reception time prediction unit is a base station transmission / reception device that transmits the downlink signal to the downlink signal. If the switching notification for notifying the switching is included, the prediction of the reception time is stopped.

Further, in the receiving device according to the present invention, the reception time prediction unit restarts the prediction when the head of the downlink signal is newly detected by the head detection unit after the prediction of the reception time is stopped. It is preferable to do so.

Further, the mobile station device according to the present invention is a mobile station device that communicates with a base station device including a plurality of base station transmission / reception devices by a time-division duplex method, and is among the plurality of base station transmission / reception devices. A mobile station transmitter / receiver that receives a downlink signal and includes a transmission parameter relating to transmission of an uplink signal from the mobile station apparatus, which is transmitted from one transmitter / receiver at the same timing in each fixed length frame, and the downlink. A head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the link signal, a reception time at the head of the downlink signal in the frame, and a frame length of the frame. Based on the above, the reception time prediction unit that predicts the reception time of the downlink signal in the next frame is provided, and the head detection unit predicts the reception time of the head of the downlink signal by the reception time prediction unit. If so, the head detection process is performed at the timing corresponding to the predicted reception time, and the reception time prediction unit switches the base station transmission / reception device for transmitting the downlink signal to the downlink signal. Offset, which is the time difference between the switching notification to be notified and the uplink signal transmitted from the mobile station device, received by the first base station transmitting / receiving device that is the switching source and the second base station transmitting / receiving device that is the switching destination. When the amount is included, the down is transmitted from the second base station transmitter / receiver based on the reception time at the beginning of the downlink signal in the frame, the frame length of the frame, and the offset amount. Predict the reception time of the link signal.

Further, the wireless communication system according to the present invention is a wireless communication system in which a base station device including a plurality of base station transmission / reception devices and a mobile station device communicate with each other, and the base station device is from the mobile station device. One base station transmission / reception that transmits a downlink signal including the transmission parameter to the mobile station device from the transmission parameter determination unit that determines the transmission parameter related to the transmission of the uplink signal and the plurality of base station transmission / reception devices. A transmission source determination unit that determines a device, a switching notification generation unit that generates a switching notification that notifies the mobile station device of switching of a base station transmission / reception device that transmits the downlink signal to the mobile station device, and the downlink. When the base station transmitter / receiver that transmits a signal to the mobile station apparatus is switched from the first base station transmitter / receiver to the second base station transmitter / receiver, the switching notification is included in the downlink signal and the first A switching unit that switches the base station transmitter / receiver that transmits the downlink signal to the mobile station apparatus at a predetermined timing to the second base station transmitter / receiver after transmitting to the mobile station apparatus via the base station transmitter / receiver. And, the mobile station apparatus is a downlink signal including the transmission parameter transmitted from one base station transmitter / receiver among the plurality of base station transmitters / receivers at the same timing in each fixed length frame. A mobile station transmission / reception device that receives A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the reception time at the head and the frame length of the frame is provided, and the head detection unit is provided by the reception time prediction unit. When the reception time at the beginning of the downlink signal is predicted, the head detection process is performed at the timing corresponding to the predicted reception time, and the reception time prediction unit notifies the downlink signal of the switching. If it is included, the prediction of the reception time is stopped.

Further, the wireless communication system according to the present invention is a wireless communication system in which a base station device including a plurality of base station transmission / reception devices and a mobile station device communicate with each other, and the base station device is from the mobile station device. One base station transmission / reception that transmits a downlink signal including the transmission parameter to the mobile station device from the transmission parameter determination unit that determines the transmission parameter related to the transmission of the uplink signal and the plurality of base station transmission / reception devices. A transmission source determination unit that determines a device, a switching notification generation unit that generates a switching notification that notifies the mobile station device of switching of a base station transmission / reception device that transmits the downlink signal to the mobile station device, and the mobile station. The time difference calculation unit that calculates the offset amount, which is the time difference between the first base station transmitter / receiver and the second base station transmitter / receiver, and the downlink signal are transmitted to the mobile station apparatus. When the base station transmitting / receiving device is switched from the first base station transmitting / receiving device to the second base station transmitting / receiving device, the switching notification and the offset amount are included in the downlink signal, and the first base is included. A switching unit that switches the base station transmitter / receiver for transmitting the downlink signal to the mobile station apparatus at a predetermined timing after transmitting to the mobile station apparatus via the station transmitter / receiver to the second base station transmitter / receiver. The mobile station apparatus receives a downlink signal including the transmission parameter transmitted at the same timing in each fixed-length frame from one of the plurality of base station transmitters / receivers. The station transmitter / receiver, the head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the downlink signal, and the reception time of the head of the downlink signal in the frame. A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the frame length of the frame, and the head detection unit includes the downlink signal by the reception time prediction unit. When the reception time at the beginning of is predicted, the head detection process is performed at the timing corresponding to the predicted reception time, and the reception time prediction unit sends the downlink signal to the switching notification and the offset. When the amount is included, the second base station transmission / reception is based on the reception time at the beginning of the downlink signal in the frame, the frame length of the frame, and the offset amount. Predict the reception time of the downlink signal transmitted from the transmitter.

According to the base station device, the mobile station device, and the wireless communication system according to the present invention, it is possible to reduce the occurrence of a reception error due to switching of the base station transmission / reception device for transmitting a DL signal.

It is a figure which shows the structural example of the wireless communication system which concerns on 1st Embodiment of this invention. It is a figure which shows the configuration example of the base station modulation / demodulation apparatus shown in FIG. It is a figure which shows the configuration example of the mobile station modulation / demodulation apparatus shown in FIG. It is a figure which shows an example of the operation of the base station apparatus and the mobile station apparatus shown in FIG. It is a figure which shows the structural example of the base station apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the structural example of the mobile station apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows an example of the operation of the base station apparatus and the mobile station apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the configuration example of the conventional wireless communication system. It is a figure for demonstrating the switching of the base station transmission / reception apparatus which transmits a DL signal. It is a figure which shows an example of the operation of the base station apparatus and the mobile station apparatus at the time of switching of the base station transmission / reception apparatus which transmits a DL signal. It is a figure for demonstrating the problem at the time of switching of the base station transmission / reception apparatus which transmits a DL signal.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a diagram showing a configuration example of a wireless communication system 1 according to the first embodiment of the present invention. In FIG. 1, the same components as those in FIG. 8 are designated by the same reference numerals, and the description thereof will be omitted.

The wireless communication system 1 shown in FIG. 1 includes a mobile station video / audio device 2, a mobile station device 10, a base station device 20, and a base station video / audio device 3. In the wireless communication system 1 shown in FIG. 1, the mobile station device 10A is changed to the mobile station device 10 and the base station device 20A is changed to the base station device 20 as compared with the wireless communication system 1A shown in FIG. The point is different.

The mobile station apparatus 10 and the base station apparatus 20 communicate with each other by a TDD system (time division duplex system). More specifically, the mobile station device 10 and the base station device 20 communicate with each other by the TDD-SVD-MIMO method. In the TDD-SVD-MIMO system, the mobile station device 10 transmits an uplink signal (UL signal) including a video / audio signal which is a program material to the base station device 20 in one fixed-length TDD frame. .. Further, the base station device 20 transmits a downlink signal (DL signal) including transmission parameters related to the transmission of the UL signal by the mobile station device 10 to the mobile station device 10. The mobile station device 10 and the base station device 20 transmit and receive signals by a MIMO method using a plurality of antennas, but since the MIMO method itself is well known, the description thereof will be omitted.

When switching one base station transmission / reception device 21 that transmits a DL signal to the mobile station device 10 among a plurality of base station transmission / reception devices 21, the base station device 20 switches the base station transmission / reception device 21 that transmits the DL signal. Is generated to the mobile station apparatus 10. The base station device 20 transmits the DL signal including the generated switching notification to the mobile station device 10 via the switching source base station transmission / reception device 21 (first base station transmission / reception device). After transmitting the DL signal including the switching notification, the base station device 20 switches the base station transmission / reception device 21 for transmitting the DL signal at a predetermined timing known by the mobile station device 10 (for example, the next TDD frame). Switch to the previous base station transmitter / receiver 21 (second base station transmitter / receiver).

When the mobile station apparatus 10 receives the DL signal including the switching notification, the mobile station apparatus 10 predicts the DL signal reception time described with reference to FIG. 10 in accordance with the switching timing of the base station transmitting / receiving apparatus 21 that transmits the DL signal. To stop. The mobile station device 10 detects the head of the DL signal transmitted from the switching destination base station transmission / reception device 21 by using only the preamble signal, as before the detection of the head of the DL signal.

Next, the configurations of the mobile station apparatus 10 and the base station apparatus 20 according to the present embodiment will be described in more detail. First, the configuration of the base station apparatus 20 according to the present embodiment will be described.

As shown in FIG. 1, the base station device 20 includes a plurality of base station transmission / reception devices 21 (base station transmission / reception devices 21-1 to 21-N) and a base station modulation / demodulation device 22.

As described with reference to FIG. 8, the plurality of base station transmission / reception devices 21 are installed at different locations. The base station transmission / reception device 21 has a predetermined communication range, and when the mobile station device 10 is present within the communication range, the base station transmission / reception device 21 can communicate with the mobile station device 10.

The base station modulation / demodulation device 22 demodulates the UL signal received by the base station transmission / reception device 21, and outputs the UL reception data (video / audio signal) to the base station video / audio device 3. Further, the base station modulation / demodulation device 22 receives DL transmission data to be transmitted to the mobile station device 10, modulates the DL transmission data and the like, and transmits the DL signal as a DL signal to the mobile station device 10 via the base station transmission / reception device 21. ..

As shown in FIG. 2, the base station modulation / demodulation device 22 includes a plurality of UL signal head detection units 221 (UL signal head detection units 221-1 to 221-N), a UL signal reception time comparison unit 222, and UL signal demodulation. A unit 223, a DL signal transmission source determination unit 224, a delay unit 225, a DL switching notification generation unit 226, a transmission parameter determination unit 227, a DL signal modulation unit 228, and a DL signal transmission source selection unit 229 are provided. ..

UL signal head detection units 221-1 to 221-N are provided corresponding to base station transmission / reception devices 21-1 to 21-N, respectively. The UL signal head detection unit 221 detects the head of the UL signal received by the corresponding base station transmission / reception device 21, and outputs the detection result together with the UL signal to the UL signal reception time comparison unit 222.

When the UL signal transmitted from the mobile station device 10 is received by the plurality of base station transmission / reception devices 21, the UL signal reception time comparison unit 222 is based on the detection result of the corresponding UL signal head detection unit 221 at each base. The reception times of UL signals in the station transmitter / receiver 21 are compared. Then, the UL signal reception time comparison unit 222 outputs the comparison result to the UL signal demodulation unit 223 together with the UL signal.

The UL signal demodulation unit 223 demodulates the UL signal output from the UL signal reception time comparison unit 222, acquires the video / audio signal (UL reception data) transmitted from the mobile station device 10, and obtains the base station video. -Output to the audio device 3. Further, the UL signal demodulation unit 223 transmits information such as MER (Modulation Error Ratio) indicating the state of the propagation path between the mobile station device 10 and the base station transmission / reception device 21 that has received the UL signal, such as the transmission parameter determination unit 227. Output to. When the UL signal transmitted from the mobile station device 10 is received by the plurality of base station transmission / reception devices 21, the UL signal demodulation unit 223 includes a plurality of base stations based on the comparison result of the UL signal reception time comparison unit 222. The UL signal received by the transmission / reception device 21 is synthesized and demolished.

The DL signal transmission source determination unit 224 as the transmission source determination unit determines one base station transmission / reception device 21 for transmitting the DL signal to the mobile station device 10 from among the plurality of base station transmission / reception devices 21. The DL signal transmission source determination unit 224 determines one base station transmission / reception device 21 for transmitting the DL signal to the mobile station device 10, for example, in response to a switching operation of the base station transmission / reception device 21 for transmitting the DL signal by the administrator. do. When the DL signal transmission source determination unit 224 determines the base station transmission / reception device 21 for transmitting the DL signal to the mobile station device 10, the determined base station transmission / reception device 21 is notified to the delay unit 225 and the DL switching notification generation unit 226. ..

The delay unit 225 is a DL signal transmission source, if necessary, so that the base station transmission / reception device 21 that transmits the DL signal in each TDD frame becomes the base station transmission / reception device 21 determined by the DL signal transmission source determination unit 224. The notification from the determination unit 224 is delayed and output to the DL signal transmission source selection unit 229.

The DL switching notification generation unit 226 as the switching notification generation unit sends a switching notification when the base station transmission / reception device 21 that transmits the DL signal to the mobile station device 10 is switched based on the notification from the DL signal transmission source determination unit 224. It is generated and output to the DL signal modulation unit 228.

The transmission parameter determination unit 227 determines transmission parameters (for example, modulation method, transmission power, etc.) related to the transmission of the UL signal by the mobile station device 10 based on the information output from the UL signal demodulation unit 223, and the DL signal modulation unit. Output to 228.

The DL signal modulation unit 228 is input with DL transmission data and transmission parameters determined by the transmission parameter determination unit 227. Further, in the DL signal modulation unit 228, when the base station transmission / reception device 21 for transmitting the DL signal is switched, the switching notification is input from the DL switching notification generation unit 226. The DL signal modulation unit 228 modulates the DL signal including the preamble signal, the transmission parameter, and the DL transmission data, and outputs the modulation to the DL signal transmission source selection unit 229. Further, when the switching notification is input, the DL signal modulation unit 228 further includes the switching notification in the DL signal and outputs the switching notification to the DL signal transmission source selection unit 229.

The DL signal transmission source selection unit 229 as a switching unit transmits the DL signal output from the DL signal modulation unit 228 to the base station transmission / reception device 21 notified from the DL signal transmission source determination unit 224 via the delay unit 225. Output. The DL signal output to the base station transmission / reception device 21 is transmitted to the mobile station device 10.

More specifically, in the DL signal transmission source selection unit 229, the base station transmission / reception device 21 for transmitting the DL signal to the mobile station device 10 is the switching source base station transmission / reception device 21 (first base station transmission / reception device). When switching to the switching destination base station transmitting / receiving device 21 (second base station transmitting / receiving device), the switching notification is included in the DL signal and transmitted to the mobile station device 10 via the switching source base station transmitting / receiving device 21. .. Further, the DL signal transmission source selection unit 229 transmits the DL signal including the switching notification to the mobile station device 10 via the switching source base station transmission / reception device 21, and then the DL signal transmission source determination unit 224 at a predetermined timing. The base station transmission / reception device 21 that outputs a DL signal is switched to the base station transmission / reception device 21 of the switching destination in accordance with the notification of. That is, the DL signal transmission source selection unit 229 transmits the DL signal including the switching notification to the mobile station device 10 via the switching source base station transmission / reception device 21, and then transmits the DL signal at a predetermined timing. The station transmission / reception device 21 is switched. The timing for switching the base station transmission / reception device 21 for transmitting the DL signal after transmitting the DL signal including the switching notification can be set, for example, after 1 TDD frame or 2 TDD frames, and the mobile station device 10 can be set. And is shared in advance by the base station apparatus 20.

Next, the configuration of the mobile station apparatus 10 will be described with reference to FIG.

As shown in FIG. 1, the mobile station device 10 includes a mobile station modulation / demodulation device 11 and a mobile station transmission / reception device 12. The mobile station modulation / demodulation device 11 receives video / audio signals from the mobile station video / audio device 2. The mobile station modulation / demodulation device 11 demodulates the input video / audio signal and transmits it as a UL signal to the base station device 20 via the mobile station transmission / reception device 12. Further, the mobile station modulation / demodulation device 11 demodulates the DL signal received by the mobile station transmission / reception device 12 and acquires transmission parameters and the like included in the DL signal.

As shown in FIG. 3, the mobile station modulation / demodulation device 11 includes a DL signal head detection unit 111, a DL signal reception time prediction unit 112, a DL signal demodulation unit 113, and a UL signal modulation unit 114.

The DL signal head detection unit 111 as the head detection unit performs head detection processing for detecting the head of the DL signal received by the mobile station transmission / reception device 12, and outputs the detection result to the DL signal reception time prediction unit 112. Further, the DL signal head detection unit 111 outputs the detection result of the head of the DL signal to the DL signal demodulation unit 113 together with the DL signal.

When the DL signal reception time prediction unit 112 as the reception time prediction unit detects the head of the DL signal received in a certain TDD frame by the DL signal head detection unit 111, the reception time of the head of the DL signal and the TDD The reception time of the DL signal in the next TDD frame is predicted based on the frame length of the frame. The DL signal reception time prediction unit 112 outputs the predicted DL signal reception time in the next TDD frame to the DL signal head detection unit 111 and the DL signal demodulation unit 113.

As described with reference to FIG. 10, the DL signal head detection unit 111 initially detects the head of the DL signal using only the preamble signal included in the DL signal. When the DL signal reception time prediction unit 112 predicts the DL signal reception time, the DL signal head detection unit 111 has a timing corresponding to the predicted reception time (for example, a predetermined time before and after the predicted reception time). In), the head detection process is performed.

The DL signal demodulation unit 113 demodulates the DL signal output from the DL signal head detection unit 111, and outputs the DL reception data included in the DL signal to the mobile station video / audio device 2. Further, the DL signal demodulation unit 113 outputs the transmission parameters included in the demodulated DL signal to the UL signal modulation unit 114. Further, when the demodulated DL signal includes a switching notification, the DL signal demodulation unit 113 causes the DL signal reception time prediction unit 112 to stop predicting the DL signal reception time. That is, in the present embodiment, the DL signal reception time prediction unit 112 stops predicting the reception time of the DL signal when the DL signal includes the switching notification.

The UL signal modulation unit 114 modulates the input UL transmission data (video / audio signal) and the like according to the transmission parameters input from the DL signal demodulation unit 113, and uses the base as a UL signal via the mobile station transmission / reception device 12. Transmission is performed to the station device 20 (base station transmission / reception device 21).

Next, the operation of the mobile station apparatus 10 and the base station apparatus 20 according to the present embodiment will be described with reference to FIG. In FIG. 4, the base station transmission / reception device 21 that transmits a DL signal to the mobile station device 10 is the base station transmission / reception device 21-1 up to the TDD frame 3, and in the TDD frame 4, the base station transmission / reception device 21-2. Suppose it can be switched. Further, the base station transmission / reception devices 21-1, 21-2 shall transmit DL signals at the same timing in each of the fixed length TDD frames.

In the TDD frame 1, the base station transmission / reception device 21-1 transmits a DL signal. The mobile station transmission / reception device 12 of the mobile station device 10 receives the DL signal transmitted from the base station transmission / reception device 21-1. The DL signal head detection unit 111 detects the head of the DL signal by using only the preamble signal included in the DL signal. The DL signal reception time prediction unit 112 predicts the reception time of the DL signal in the next TDD frame (TDD frame 2) based on the detection time at the beginning of the DL signal and the frame length of the TDD frame.

In the TDD frame 2, the base station transmission / reception device 21-1 transmits a DL signal. The mobile station transmission / reception device 12 receives the DL signal transmitted from the base station transmission / reception device 21-1. The DL signal head detection unit 111 performs head detection processing at a timing corresponding to the reception time predicted by the DL signal reception time prediction unit 112. The DL signal reception time prediction unit 112 predicts the reception time of the DL signal in the next TDD frame (TDD frame 3), similarly to the TDD frame 1.

In the TDD frame 3, the base station transmission / reception device 21-1 transmits a DL signal. Here, in the next TDD frame 4, the base station transmission / reception device 21 that transmits the DL signal to the mobile station device 10 is switched from the base station transmission / reception device 21-1 to the base station transmission / reception device 21-2, so that the DL switching notification is generated. The unit 226 generates a switching notification and outputs it to the DL signal modulation unit 228. The DL signal modulation unit 228 modulates the DL signal including the switching notification and outputs it to the DL signal transmission source selection unit 219. The DL signal transmission source selection unit 219 transmits the DL signal output from the DL signal modulation unit 218 to the mobile station device 10 via the base station transmission / reception device 21-1 which is the switching source.

The mobile station transmission / reception device 12 of the mobile station device 10 receives the DL signal transmitted from the base station transmission / reception device 21-1. The DL signal head detection unit 111 performs head detection processing at a timing corresponding to the reception time predicted by the DL signal reception time prediction unit 112, and outputs the DL signal to the DL signal demodulation unit 113. The DL signal demodulation unit 113 demodulates the DL signal output from the DL signal head detection unit 111. As described above, in the TDD frame 3, since the DL signal includes the switching notification, the DL signal reception time prediction unit 112 stops predicting the reception time of the DL signal in the next frame (TDD frame 4).

In the TDD frame 4, the base station transmission / reception device 21 that transmits the DL signal to the mobile station device 10 is switched from the base station transmission / reception device 21-1 to the base station transmission / reception device 21-2. Therefore, the DL signal transmission source selection unit 229 transmits the DL signal to the mobile station device 10 via the base station transmission / reception device 21-2.

The mobile station transmission / reception device 12 receives the DL signal transmitted from the base station transmission / reception device 21-1. As described above, in the TDD frame 3, the DL signal reception time is not predicted by the DL signal reception time prediction unit 112. Therefore, the DL signal head detection unit 111 detects the head of the DL signal by using only the preamble signal included in the DL signal. The DL signal reception time prediction unit 112 predicts the reception time of the DL signal in the next TDD frame (TDD frame 5) based on the detection time at the beginning of the DL signal and the frame length of the TDD frame. That is, the DL signal reception time prediction unit 112 restarts the prediction of the reception time when the head of the DL signal is newly detected by the DL signal head detection unit 111 after the reception time prediction is stopped. By doing so, it is possible to improve the detection accuracy of the head of the DL signal after switching the base station transmission / reception device 21 for transmitting the DL signal.

As described above, in the present embodiment, when the base station apparatus 20 switches the base station transmitting / receiving apparatus 21 that transmits the DL signal to the mobile station apparatus 10, the switching notification is included in the DL signal. When the DL signal includes the switching notification, the mobile station apparatus 10 stops predicting the reception time using the frame length of the TDD frame.

Therefore, even if the timing at which the DL signal reaches the mobile station device 10 changes due to the switching of the base station transmission / reception device 21 that transmits the DL signal, the head of the DL signal can be detected by the head detection process. , The occurrence of reception error can be suppressed.

(Second embodiment)
FIG. 5 is a diagram showing a configuration example of the base station device 40 according to the second embodiment of the present invention. FIG. 6 is a diagram showing a configuration example of the mobile station device 30 according to the second embodiment of the present invention. In FIG. 5, the same components as those in FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted. Further, in FIG. 6, the same reference numerals are given to the same configurations as those in FIG. 3, and the description thereof will be omitted. The mobile station apparatus 30 and the base station apparatus 40 according to the present embodiment communicate by the TDD-SVD-MIMO method in the same manner as the mobile station apparatus 10 and the base station apparatus 20 according to the first embodiment. First, the configuration of the base station apparatus 40 will be described.

As shown in FIG. 5, the base station device 40 includes a plurality of base station transmission / reception devices 21 and a base station modulation / demodulation device 42. The base station device 40 shown in FIG. 5 is different from the base station device 20 shown in FIG. 2 in that the base station modulation / demodulation device 22 is changed to the base station modulation / demodulation device 42.

The base station modulation / demodulation device 42 includes a plurality of UL signal head detection units 221, UL signal reception time comparison unit 222, UL signal demodulation unit 223, DL signal transmission source determination unit 224, delay unit 225, and DL switching notification. It includes a generation unit 226, a transmission parameter determination unit 227, a DL transmission source selection unit 229, a time difference calculation unit 421, and a DL signal modulation unit 422. The base station modulation / demodulation device 42 shown in FIG. 5 has a time difference calculation unit 421 added and a DL signal modulation unit 228 changed to a DL signal modulation unit 428 as compared with the base station modulation / demodulation device 22 shown in FIG. Is different.

When the DL signal transmission source determination unit 224 determines the switching of the base station transmission / reception device 21 for transmitting the DL signal, the time difference calculation unit 421 determines the mobile station device 10 based on the comparison result by the UL signal reception time comparison unit 222. The offset amount, which is the time difference between the switching source base station transmission / reception device 21 and the switching destination base station transmission / reception device 21, is calculated. The time difference calculation unit 421 outputs the calculated offset amount to the DL signal modulation unit 422.

When the offset amount is output from the time difference calculation unit 421, the DL signal modulation unit 422 modulates the DL signal including the switching notification and the offset amount, and outputs the DL signal to the DL transmission source selection unit 229. The DL transmission source selection unit 229 transmits the DL signal including the switching notification and the offset amount output from the DL signal transmission source selection unit 229 to the mobile station device 30 via the base station transmission / reception device 21 of the switching source. That is, the DL transmission source selection unit 229 as the switching unit includes the switching notification and the offset amount in the DL signal, and the mobile station device 30 via the switching source base station transmission / reception device 21 (first base station transmission / reception device). Send to.

Next, the configuration of the mobile station device 30 will be described.

As shown in FIG. 6, the mobile station device 30 includes a mobile station modulation / demodulation device 31 and a mobile station transmission / reception device 12. The mobile station apparatus 30 shown in FIG. 6 is different from the mobile station apparatus 10 shown in FIG. 3 in that the mobile station modulation / demodulation device 11 is changed to the mobile station modulation / demodulation device 31.

The mobile station modulation / demodulation device 31 includes a DL signal head detection unit 111, a DL signal reception time prediction unit 312, a DL signal demodulation unit 313, and a UL signal modulation unit 114. The mobile station modulation / demodulation device 31 shown in FIG. 6 has a DL signal reception time prediction unit 112 and a DL signal demodulation unit 113, respectively, as compared with the mobile station modulation / demodulation device 11 shown in FIG. The difference is that it is changed to the signal demodulation unit 313.

The DL signal demodulation unit 313 demodulates the DL signal received by the mobile station transmission / reception device 12, and outputs the offset amount to the DL signal reception time prediction unit 312 when the DL signal includes a switching notification and an offset amount.

When the head of the DL signal received in a certain TDD frame is detected by the DL signal head detection unit 311, the DL signal reception time prediction unit 312 is based on the reception time of the head of the DL signal and the frame length of the TDD frame. Predict the reception time of the DL signal in the next TDD frame. In the present embodiment, when the offset amount is input from the DL signal demodulation unit 313, the DL signal reception time prediction unit 312 has the reception time at the beginning of the DL signal in a certain TDD frame, the frame length of the TDD frame, and the offset. Based on the quantity, the reception time of the DL signal in the next TDD frame is predicted. Specifically, the DL signal reception time prediction unit 312 adds the frame length of the TDD frame to the reception time at the beginning of the DL signal in one TDD frame, and sets the time obtained by increasing or decreasing by the offset amount as the DL in the next TDD frame. Predict the signal reception time.

Next, the operation of the mobile station device 30 and the base station device 40 according to the present embodiment will be described with reference to FIG. 7. In FIG. 7, the base station transmission / reception device 21 that transmits the DL signal to the mobile station device 30 is the base station transmission / reception device 21-1 up to the TDD frame 3, and is switched to the base station transmission / reception device 21-2 in the TDD frame 4. It is supposed to be done. Since the steps up to the TDD frame 2 are the same as those in FIG. 4, the description thereof will be omitted.

In the TDD frame 3, the base station transmission / reception device 21-1 transmits a DL signal. Here, in the next TDD frame 4, the base station transmission / reception device 21 that transmits the DL signal to the mobile station device 30 is switched from the base station transmission / reception device 21-1 to the base station transmission / reception device 21-2, so that the DL switching notification is generated. The unit 226 generates a switching notification and outputs it to the DL signal modulation unit 228. Further, the time difference calculation unit 421 is an offset amount which is the time difference between the base station transmission / reception device 21-1 which is the switching source and the base station transmission / reception device 21-2 which is the switching destination to receive the UL signal from the mobile station device 30. To calculate. The DL signal modulation unit 422 modulates the DL signal including the switching notification and the offset amount, and outputs the modulation to the DL signal transmission source selection unit 219. The DL signal transmission source selection unit 219 transmits the DL signal output from the DL signal modulation unit 422 to the mobile station device 30 via the base station transmission / reception device 21-1 which is the switching source.

The mobile station transmission / reception device 12 of the mobile station device 30 receives the DL signal transmitted from the base station transmission / reception device 21-1. The DL signal head detection unit 111 performs head detection processing at a timing corresponding to the reception time predicted by the DL signal reception time prediction unit 112. The DL signal demodulation unit 313 demodulates the received DL signal and outputs the offset amount included in the DL signal to the DL signal reception time prediction unit 312. The DL signal reception time prediction unit 312 estimates the reception time in the TDD frame 4 based on the reception time at the beginning of the DL signal in the TDD frame 3, the frame length of the TDD frame, and the offset amount.

In the TDD frame 4, similarly to FIG. 4, the head of the DL signal transmitted by the base station transmission / reception device 21-2 is detected at the timing corresponding to the reception time predicted by the DL signal reception time prediction unit 312.

As described above, in the present embodiment, when the base station device 40 switches the base station transmission / reception device 21 that transmits the DL signal to the mobile station device 30, the base station device 40 sends the DL signal including the switching notification and the offset amount to the base station of the switching source. Transmission is performed via the transmission / reception device 21. The mobile station apparatus 30 predicts the reception time of the DL signal in the next TDD frame based on the reception time of the beginning of the DL signal in the TDD frame, the frame length of the TDD frame, and the offset amount.

Therefore, even if the timing at which the DL signal reaches the mobile station device 10 changes due to the switching of the base station transmission / reception device 21 that transmits the DL signal, the head of the DL signal is detected in consideration of the change. Therefore, it is possible to suppress the occurrence of reception errors.

In the first and second embodiments described above, the switching notification is transmitted in the TDD frame immediately before the TDD frame for switching the base station transmission / reception device 21 for transmitting the DL signal to the mobile station devices 10 and 30. Although the explanation has been given using an example, the present invention is not limited to this. For example, the switching notification may be transmitted over a plurality of TDD frames before the TDD frame for switching the base station transmitting / receiving device 21 for transmitting the DL signal to the mobile station devices 10 and 30. Further, after transmitting the switching notification, the base station transmitting / receiving device 21 that transmits the DL signal to the mobile station devices 10 and 30 may be switched after several frames.

Although not particularly mentioned in the embodiment, a program may be provided in which the computer functions as the mobile station devices 10 and 30 or the base station devices 20 and 40. The program may also be recorded on a computer-readable medium. It can be installed on a computer using a computer-readable medium. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, but may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

Alternatively, the mobile station apparatus 10 is composed of a memory for storing a program for executing each process performed by the mobile station apparatus 10, 30 or the base station apparatus 20, 40, and a processor for executing the program stored in the memory. , 30 or chips mounted on base station devices 20, 40 may be provided.

Although the above embodiments have been described as representative examples, it will be apparent to those skilled in the art that many modifications and substitutions are possible within the spirit and scope of the invention. Therefore, the invention should not be construed as limiting by the embodiments described above, and various modifications and modifications can be made without departing from the claims. For example, it is possible to combine a plurality of the constituent blocks described in the configuration diagram of the embodiment into one, or to divide one constituent block into one.

1,1A wireless communication system 2 Mobile station video / audio device 3 Base station video / audio device 10,30 Mobile station device 11 Mobile station modulation / demodulation device 12 Mobile station transmitter / receiver 20,40 Base station appliance 21 Base station transmitter / receiver 22,42 Base station modulation / demodulator 111 DL signal head detection unit (head detection unit)
112, 312 DL signal reception time prediction unit (reception time prediction unit)
113,313 DL signal demodulation unit 114 UL signal modulation unit 221 UL signal head detection unit 222 UL signal reception time comparison unit 223 UL signal demodulation unit 224 DL signal transmission source determination unit (source determination unit)
225 Delay unit 226 DL switching notification generation unit (switching notification generation unit)
227 Transmission parameter determination unit 228,422 DL signal modulation unit 229 DL signal source selection unit (switching unit)
421 Time difference calculation unit

Claims (7)

A base station device that communicates with a mobile station device by a time division duplex system via a plurality of base station transmitter / receiver devices.
A transmission parameter determination unit that determines transmission parameters related to transmission of uplink signals from the mobile station device, and a transmission parameter determination unit.
A transmission source determination unit that determines one base station transmission / reception device that transmits a downlink signal including the transmission parameter to the mobile station device from the plurality of base station transmission / reception devices.
A switching notification generation unit that generates a switching notification for notifying the mobile station device of switching of the base station transmitting / receiving device that transmits the downlink signal to the mobile station device.
When the base station transmitter / receiver that transmits the downlink signal to the mobile station apparatus is switched from the first base station transmitter / receiver to the second base station transmitter / receiver, the switching notification is included in the downlink signal. The base station transmitter / receiver that transmits the downlink signal to the mobile station apparatus at a predetermined timing after being transmitted to the mobile station apparatus via the first base station transmitter / receiver is used as the second base station transmitter / receiver. A base station device equipped with a switching unit for switching. In the base station apparatus according to claim 1,
Further, a time difference calculation unit for calculating an offset amount, which is a time difference between receiving an uplink signal from the mobile station device between the first base station transmission / reception device and the second base station transmission / reception device, is provided.
The switching unit includes the switching notification and the offset amount in the downlink signal and transmits the switching notification to the mobile station device via the first base station transmitting / receiving device. A mobile station device that communicates with a base station device equipped with a plurality of base station transmitter / receiver devices by a time division duplex system.
A downlink including a transmission parameter relating to transmission of an uplink signal from the mobile station device, which is transmitted from one base station transmitter / receiver among the plurality of base station transmitters / receivers at the same timing in each fixed-length frame. A mobile station transmitter / receiver that receives signals,
A head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the downlink signal, and
A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the reception time at the beginning of the downlink signal in the frame and the frame length of the frame is provided.
When the reception time at the beginning of the downlink signal is predicted by the reception time prediction unit, the head detection unit performs the head detection process at a timing corresponding to the predicted reception time.
The reception time prediction unit stops the prediction of the reception time when the downlink signal includes a switching notification notifying the switching of the base station transmission / reception device that transmits the downlink signal. .. In the mobile station apparatus according to claim 3,
The reception time prediction unit is a mobile station apparatus that restarts the prediction when the head of the downlink signal is newly detected by the head detection unit after the reception time prediction is stopped. A mobile station device that communicates with a base station device equipped with a plurality of base station transmitter / receiver devices by a time division duplex system.
A downlink signal including a transmission parameter relating to transmission of an uplink signal from the mobile station apparatus, which is transmitted from one of the plurality of base station transmitters / receivers at the same timing in each fixed-length frame. Mobile station transmitter / receiver to receive and
A head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the downlink signal, and
A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the reception time at the beginning of the downlink signal in the frame and the frame length of the frame is provided.
When the reception time at the beginning of the downlink signal is predicted by the reception time prediction unit, the head detection unit performs the head detection process at a timing corresponding to the predicted reception time.
The reception time prediction unit is a switching source of a switching notification notifying the downlink signal of switching of the base station transmitting / receiving device for transmitting the downlink signal and an uplink signal transmitted from the mobile station device. When the offset amount, which is the time difference between the first base station transmitter / receiver and the second base station transmitter / receiver to be switched, is included, the reception time at the beginning of the downlink signal in the frame and the reception time at the beginning of the downlink signal in the frame are included. A mobile station device that predicts the reception time of a downlink signal transmitted from the second base station transmission / reception device based on the frame length of the frame and the offset amount. A wireless communication system in which a base station device having a plurality of base station transmitters / receivers and a mobile station device communicate with each other.
The base station device is
A transmission parameter determination unit that determines transmission parameters related to transmission of uplink signals from the mobile station device, and a transmission parameter determination unit.
A transmission source determination unit that determines one base station transmission / reception device that transmits a downlink signal including the transmission parameter to the mobile station device from the plurality of base station transmission / reception devices.
A switching notification generation unit that generates a switching notification for notifying the mobile station device of switching of the base station transmitting / receiving device that transmits the downlink signal to the mobile station device.
When the base station transmitter / receiver that transmits the downlink signal to the mobile station apparatus is switched from the first base station transmitter / receiver to the second base station transmitter / receiver, the switching notification is included in the downlink signal. The base station transmitter / receiver that transmits the downlink signal to the mobile station apparatus at a predetermined timing after being transmitted to the mobile station apparatus via the first base station transmitter / receiver is used as the second base station transmitter / receiver. Equipped with a switching unit to switch
The mobile station device is
A mobile station transmitter / receiver that receives a downlink signal including the transmission parameter transmitted at the same timing in each of the fixed-length frames from one base station transmitter / receiver among the plurality of base station transmitters / receivers.
A head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the downlink signal, and
A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the reception time at the beginning of the downlink signal in the frame and the frame length of the frame is provided.
When the reception time at the beginning of the downlink signal is predicted by the reception time prediction unit, the head detection unit performs the head detection process at a timing corresponding to the predicted reception time.
The reception time prediction unit is a wireless communication system that stops predicting the reception time when the downlink signal includes the switching notification. A wireless communication system in which a base station device having a plurality of base station transmitters / receivers and a mobile station device communicate with each other.
The base station device is
A transmission parameter determination unit that determines transmission parameters related to transmission of uplink signals from the mobile station device, and a transmission parameter determination unit.
A transmission source determination unit that determines one base station transmission / reception device that transmits a downlink signal including the transmission parameter to the mobile station device from the plurality of base station transmission / reception devices.
A switching notification generation unit that generates a switching notification for notifying the mobile station device of switching of the base station transmitting / receiving device that transmits the downlink signal to the mobile station device.
A time difference calculation unit that calculates an offset amount, which is a time difference between the first base station transmitter / receiver and the second base station transmitter / receiver, for receiving the uplink signal from the mobile station apparatus.
When the base station transmission / reception device that transmits the downlink signal to the mobile station device is switched from the first base station transmission / reception device to the second base station transmission / reception device, the switching notification and the offset amount are reduced. The second base station transmitter / receiver, which is included in the link signal and transmitted to the mobile station apparatus via the first base station transmitter / receiver, and then transmits the downlink signal to the mobile station apparatus at a predetermined timing. Equipped with a switching unit that switches to the base station transmitter / receiver
The mobile station device is
A mobile station transmitter / receiver that receives a downlink signal including the transmission parameter transmitted at the same timing in each fixed-length frame from one of the plurality of base station transmitters / receivers.
A head detection unit that performs head detection processing to detect the head of the downlink signal based on the preamble signal included at the head of the downlink signal, and
A reception time prediction unit that predicts the reception time of the downlink signal in the next frame based on the reception time at the beginning of the downlink signal in the frame and the frame length of the frame is provided.
When the reception time at the beginning of the downlink signal is predicted by the reception time prediction unit, the head detection unit performs the head detection process at a timing corresponding to the predicted reception time.
When the downlink signal includes the switching notification and the offset amount, the reception time prediction unit determines the reception time at the beginning of the downlink signal in the frame, the frame length of the frame, and the frame length. A wireless communication system that predicts the reception time of a downlink signal transmitted from the second base station transmitter / receiver based on the offset amount.

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