JP2001230746A - Radio communication method and equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a mobile station accurately detect a frame timing in a radio communication system for taking frame synchronization with each other. SOLUTION: In this radio communication system of a time division multiplex/ time division multiple access communication system for establishing synchronization of the frame timing among respective base stations and separating the using time of the respective base stations so as to utilize the same frequency among the respective base stations, by making the respective base stations transmit adjustment contents at the time of adjusting their own frame timings, the mobile station easily estimates the next frame. Thus, the synchronization is held at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication method and apparatus suitable for use in a radio system of a time division multiplex / time division multiple access communication system in which the use times of a plurality of base stations are separated.

[0002]

2. Description of the Related Art A conventional wireless communication system is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-154939.
A certain base station recognizes a frame signal transmitted from another adjacent base station and determines a transmission timing of a frame signal to be transmitted by itself based on the transmission frame signal. In this case, the mobile station communicating with the base station widens the window for receiving the frame signal in anticipation of the base station changing the transmission timing of the frame signal.

FIG. 9 is a block diagram showing a configuration of a conventional wireless communication system. In this figure, the base station 10
Receiver 11 and adjacent base station frame timing detector 1
2, a frame timing generator 13, a frame signal generator 14, and a transmitter 15.

[0004] Adjacent base station frame timing detector 12
Detects a frame signal transmitted by an adjacent base station from information received from the receiving unit 11. The frame timing generator 13 generates the transmission timing of the frame signal transmitted by itself from the adjacent base station frame timing detection signal from the adjacent base station frame timing detector 12. The frame signal generation unit 14
A frame signal is generated based on the frame signal transmission timing from the. The transmission unit 15 includes the frame signal generation unit 1
The frame signal generated in step 4 is transmitted.

On the other hand, the mobile station 30 includes a receiving unit 31, a frame signal detecting unit 32, and a frame timing control unit 33.
And a frame timing reproducing unit 34. The frame signal detector 32 detects a frame signal from information received from the receiver 31. The frame timing control unit 33 determines the frame timing position of the next frame based on the frame signal detection signal detected by the frame signal detection unit 32. The frame timing reproducing unit 34 generates a frame timing based on the frame timing control information from the frame timing control unit 33.

In the conventional radio communication system having such a configuration, the base station 10 detects a frame signal of an adjacent base station, changes the transmission timing of the frame signal transmitted by itself, and the mobile station 30 The frame timing of the base station 10 is recognized.

[0007]

However, in the conventional radio communication system, when the same frequency is used between a plurality of base stations, the base stations detect frame signals and synchronize with each other by synchronizing the frame signals. Although the bands are not overlapped, the mobile station cannot know that the base stations are in frame synchronization with each other, so in anticipation of the base station changing the transmission timing of the frame signal, In this case, there is a problem that the probability of erroneous detection of the frame signal increases due to the need to keep a wide window for receiving the frame signal.

[0008] OFDM (Orthogonal Frequency D)
In a wireless communication system using an ivision multiplexing (ivision multiplexing) transmission system, by performing statistical processing such as averaging timings detected in the past, frame signal timings and symbol synchronization timings can be detected more accurately, and transmission characteristics are improved. be able to. However, in the above-described wireless communication system that maintains frame synchronization, a plurality of base stations are separated from each other so that wireless bands do not overlap with each other, so that the frame timing of each base station is not periodic. Therefore, the mobile station cannot perform statistical processing such as averaging frame timings detected in the past, and cannot improve transmission characteristics.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a radio communication method and apparatus in which a mobile station can accurately detect a frame timing in a radio communication system that synchronizes frames. And

[0010]

According to the radio communication method of the present invention, when a base station adjusts its own frame timing, the base station transmits a notification signal to notify the mobile station connected to the base station of the adjustment, and transmits the notification signal. The reception of the mobile station estimates the frame timing of the next frame.

Further, according to the radio communication method of the present invention, when the base station adjusts its own frame timing, the base station transmits a broadcast signal for notifying the mobile station connected to the base station of the adjustment amount, and the mobile station transmits the broadcast signal to the mobile station. Upon reception, the frame timing of the next frame is estimated.

Further, according to the radio communication method of the present invention, when the base station adjusts its own frame timing, the base station transmits a broadcast signal informing a mobile station connected to the base station of a direction to adjust the frame timing, and transmits the broadcast signal. The reception of the mobile station estimates the frame timing of the next frame.

Further, according to the radio communication method of the present invention, when the base station adjusts its own frame timing, the base station transmits a broadcast signal for notifying the mobile station connected to itself of the direction and amount of adjustment of the frame timing, The mobile station receives the broadcast signal and estimates the frame timing of the next frame.

[0014] According to these methods, the mobile station can detect the frame timing with high accuracy, and the transmission characteristics can be improved.

The base station apparatus according to the present invention comprises: an adjacent base station frame timing detecting means for generating adjacent base station frame timing information from a received signal from an adjacent base station; Transmission frame timing control means for generating timing information indicating the transmission timing of the frame signal to be transmitted this time based on the timing information indicating the transmission timing, and generating timing change information indicating whether or not the transmission timing has been changed, A frame signal generating means for generating a frame signal including the timing change information.

Further, in the base station apparatus according to the present invention, in the base station apparatus, the transmission frame timing control means outputs timing change information indicating a change amount of the transmission timing instead of whether the transmission timing is changed. Take.

Further, in the base station apparatus according to the present invention, in the base station apparatus, the transmission frame timing control means outputs a timing change notification signal indicating a direction of the transmission timing change instead of the presence or absence of the transmission timing change. It adopts the configuration to do.

Further, in the base station apparatus according to the present invention, in the base station apparatus, the transmission frame timing control means includes, in addition to the presence / absence of the transmission timing change, timing change information indicating the direction and amount of change of the transmission timing. Is adopted.

The mobile station apparatus of the present invention employs a configuration including a frame timing control means for estimating the frame timing of the next frame based on the timing change information transmitted from the base station apparatus.

According to these configurations, the mobile station can accurately detect the frame timing, and the transmission characteristics can be improved.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention is that when a base station changes its own frame timing, it notifies the mobile station of the change.

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

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a radio communication system according to Embodiment 1 of the present invention. Note that, in this figure, the same parts as those in FIG. 9 described above are denoted by the same reference numerals.

In this figure, a base station (base station device) 1
0 is a receiving unit 11, an adjacent base station frame timing detecting unit 12 that detects a transmission frame signal from an adjacent base station from information received from the receiving unit 11 and generates adjacent base station frame timing information, A frame timing generation unit 13 that generates a frame timing signal (timing information) from a frame signal transmission timing signal indicating a transmission timing, an adjacent base station frame timing information generated by the adjacent base station frame timing detection unit 12, and a frame timing generation A transmission timing of a frame signal to be transmitted this time is generated based on the frame timing signal generated by the unit 13 and output as a frame signal transmission timing signal, and a timing change notification signal indicating whether or not the transmission timing has been changed ( Notification signal, timing Further, the transmission frame timing control unit 16 generates and outputs the additional information), and includes information indicating whether there is a change in the frame timing from the timing change notification signal generated by the transmission frame timing control unit 16 and indicating the presence or absence of the change. And a frame signal generation unit 17 that generates a frame signal and outputs the frame signal to the transmission unit 15 in accordance with the current frame signal transmission timing signal generated by the transmission frame timing control unit 16.

The frame timing generator 13 generates a frame timing signal from the frame signal transmission timing signal generated by the transmission frame timing controller 16.

On the other hand, the mobile station (mobile station apparatus) 30 receives the reception information from the reception section 31, and detects a frame signal from the reception information, outputs a frame signal detection signal, and outputs a frame signal detection signal. A frame signal detection unit 35 for outputting a change notification detection signal (timing change information); and a frame timing of the next frame using statistical processing based on the frame signal detection signal detected by the frame signal detection unit 35 and the timing change notification detection signal. Timing control unit 36 for estimating
6. A frame timing reproducing unit 34 for generating a frame timing based on the frame timing control information from
And is provided. As an example of the statistical processing in the frame timing control unit 36, there is a processing for averaging the frame timing detected in the past and the frame timing currently detected.

Here, as shown in FIG. 2, it is assumed that two base stations 10-1 and 10-2 are arranged at positions where the serviceable range overlaps and communicate with mobile station 30 using the same frequency. Think. As shown in FIG. 3, two base stations 10
-1, 10-2 shift the transmission timing so that the wireless bands do not overlap with each other in terms of time. In this example,
Each of the base stations 10-1 and 10-2 uses a frame timing cycle of 2 msec and divides a frame length of 2 msec into two.

The base station 10-1 converts the frame signal S1 into
At the position of t1, transmission is performed at a period of 2 msec, and the base station 10-2
Transmits the frame signal S2 at the position of t2 at a period of 2 msec, and shifts the band that can be used by each in time. That is, each of the base stations 10-1 and 10-2
The frame signals of the other party are mutually detected, and the time unit of 2 msec is divided into two and separated.

Next, let us consider a case where a third base station 10-3 is newly installed in a state where the two base stations 10-1 and 10-2 are separated from each other as shown in FIG. As shown in FIG. 5A, two base stations 10-1, 10-
When the second base station 10-3 newly enters the position at the time t3 in a state where the two base stations are segregated in time, the three base stations 10-1, 10-2, and 10-3 become While detecting the frame timing from each other's frame signals, as shown in FIG. 5B, the 2 msec frame is divided into three and used. That is, each base station 1
0-1, 10-2, and 10-3 detect a frame signal transmitted by another base station from the state of FIG. 5A and adjust the timing of the frame signal transmitted by the own base station to adjust the timing of the frame signal transmitted by itself. To the state shown in FIG.

In the process of transitioning from the state a) to the state b) in FIG. 5, each of the base stations 10-1, 10-2, and 10-3 transmits the timing adjustment contents of the frame signal transmitted by itself to the frame signal message. To notify the mobile station 30 connected to itself.

Next, the operation of the wireless communication system having the above configuration will be described. First, the operation of the base station 10 will be described. A frame signal transmitted from the adjacent base station is detected from the received information, and a frame signal transmission timing signal is generated from the adjacent base station frame timing information and the previously generated frame timing information. At the same time, it generates a timing change notification signal indicating whether or not the frame timing has been changed. Then, the presence / absence of a change in the frame timing is recognized from the timing change notification signal, a frame signal including information indicating the presence / absence of the change is generated, and the frame signal is output to the transmission unit 15 according to the frame signal transmission timing signal. Further, the base station 10 generates the next frame timing based on the frame signal transmission timing signal generated this time.

On the other hand, the mobile station 30 detects the frame signal from the received information, performs statistical processing, and estimates the frame timing of the next frame. In this case, when a timing change notification signal indicating that there is a frame timing change is detected in the received frame signal, the weight of the currently detected timing in the statistical processing is increased, or only the currently detected frame timing is performed without performing the statistical processing. Then, the method of estimating the next frame timing is switched.

As described above, according to the present embodiment, mobile station 30 is notified of the presence / absence of a change in frame timing of base station 10, so that mobile station 30 has a wide window for receiving a frame signal. This eliminates the necessity, and the frame timing can be detected with high accuracy.

(Embodiment 2) FIG. 6 is a block diagram showing a configuration of a radio communication system according to Embodiment 2 of the present invention. In this figure, the same parts as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

In the base station 10, the transmission frame timing control unit 18 outputs a timing change amount notification signal (timing change notification signal (broadcasting signal, timing change information)) indicating the amount of change, not whether the frame timing has changed. I do. The frame signal generation unit 17 generates a frame signal including information indicating the amount of change in frame timing from the transmission frame timing control unit 18 and outputs the frame signal to the transmission unit 15 according to the frame signal transmission timing signal.

On the other hand, in the mobile station 30, the frame signal detection unit 35 receives the reception information from the reception unit 31, detects the frame signal, and changes the timing of the frame signal detection signal and the timing change amount notification information in the frame signal. Output as a notification amount detection signal. The frame timing controller 36 performs statistical processing on the frame timing detected by the frame signal detector 35. In this case, a frame timing estimation result of the next frame is output according to the timing change notification amount. For example, when averaging the previously detected frame timing and the currently detected frame timing, the weight of the currently detected timing is increased or decreased according to the timing change notification amount. , The next frame timing estimation method is switched.

As described above, according to the present embodiment, base station 10 notifies mobile station 30 of not only the presence / absence of frame timing change but also the amount of change. The frame timing can be detected with higher accuracy than in the case of 1.

(Embodiment 3) FIG. 7 is a block diagram showing a configuration of a radio communication system according to Embodiment 3 of the present invention. In this figure, the same parts as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

In the base station 10, the transmission frame timing control unit 19 sends a timing change direction notification signal (timing change notification signal (broadcast signal, frame change information)) indicating the direction of the change, not whether the frame timing has changed. Output. The frame signal generation unit 17 generates a frame signal including information indicating the frame timing change direction from the transmission frame timing control unit 19, and transmits the frame signal in accordance with the frame signal transmission timing signal.
Output to 5

On the other hand, in the mobile station 30, the frame signal detecting section 35 detects a frame signal from the information received from the receiving section 31, and notifies the frame signal detection signal and the timing change direction notification information in the frame signal of the timing change direction. Output as a detection signal. The frame timing controller 36 performs statistical processing on the frame timing detected by the frame signal detector 35. In this case, the method of estimating the frame timing of the next frame is switched according to the timing change direction notification detection signal, the next frame timing is estimated, and the result is output to the frame timing reproducing unit 34. For example, if the directionality of the difference between the currently detected frame timing and the frame timing estimated from the past frame timing is different from the timing change direction notification information, the reliability of the currently detected frame timing is reduced. The next frame timing is estimated by treating it as low or erroneous detection.

As described above, according to the present embodiment, base station 10 notifies mobile station 30 of not only the presence / absence of frame timing change, but also the direction of change, so that mobile station 30 can execute the above-described embodiment. The frame timing can be detected with higher accuracy than in the first embodiment.

(Embodiment 4) FIG. 8 is a block diagram showing a configuration of a radio communication system according to Embodiment 4 of the present invention. In this figure, the same parts as those in FIG. 1 described above are denoted by the same reference numerals, and description thereof will be omitted.

In the base station 10, the transmission frame timing control unit 20 determines whether or not the frame timing has changed, as well as a timing change amount / direction notification signal (a timing change notification signal (broadcast signal,
Output timing change information)). The frame signal generation unit 17 generates a frame signal including information indicating the frame timing change amount / change direction from the transmission frame timing control unit 20 and outputs the frame signal to the transmission unit 15 according to the frame signal transmission timing signal.

On the other hand, in the mobile station 30, the frame signal detector 35 detects the frame signal from the information received from the receiver 31, and changes the timing of the frame signal detection signal and the timing change amount / direction notification information in the frame signal. Output as the amount / direction notification detection signal. The frame timing control unit 36 performs statistical processing on the detected frame timing. In this case, the method of estimating the frame timing of the next frame is switched according to the timing change amount / direction notification detection signal, the next frame timing is estimated, and the result is output to the frame timing reproducing unit 34.

As described above, in the present embodiment, unlike the above-described first to third embodiments, the mobile station 30 notifies the mobile station of the change amount and the change direction of the frame timing. Therefore, the mobile station 30 detects the frame timing with high accuracy. I can do it.

The information on the change amount and the change direction of the frame timing notified from the base station 10 to the mobile station 30 is the information indicating the timing of transmitting the next frame signal. It is also possible to make a transition from the state shown to the state shown in b) in one frame. Further, in the present embodiment, since the mobile station 30 can accurately know the details of the adjustment of the frame timing of the base station 10, it is sufficient to perform the receiving operation at the timing at which the frame signal can be actually received. Can also be expected.

[0047]

As described above, according to the present invention,
Since the presence or absence of a change in the frame timing of the base station is notified to the mobile station, frame timing detection in the mobile station can be performed with high accuracy, and transmission characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a wireless communication system according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram of an operation of the wireless communication system according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of an operation of the wireless communication system according to the first embodiment of the present invention.

FIG. 4 is an explanatory diagram of an operation of the wireless communication system according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram of an operation of the wireless communication system according to the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a wireless communication system according to Embodiment 2 of the present invention.

FIG. 7 is a block diagram showing a configuration of a wireless communication system according to a third embodiment of the present invention.

FIG. 8 is a block diagram showing a configuration of a wireless communication system according to a fourth embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a conventional wireless communication system.

[Explanation of symbols]

Reference Signs List 10 base station 11 receiving unit 12 adjacent base station frame timing detecting unit 13 frame timing generating unit 15 transmitting unit 16, 18, 19, 20 transmitting frame timing controlling unit 17 frame signal generating unit 30 mobile station 31 receiving unit 34 frame timing reproducing unit 35 frame signal detector 36 frame timing controller

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K028 BB04 CC02 CC05 DD01 DD02 EE05 EE07 KK12 LL02 MM04 NN01 NN43 NN44 NN59 RR01 5K047 AA03 AA11 BB01 CC02 DD01 DD02 GG44 GG57 HH01 HH12 HH21 HH32 A06 BB06 EE04 EE10 JJ00

Claims (9)

[Claims] When a base station adjusts its own frame timing, the base station transmits a broadcast signal to notify the mobile station connected to the base station of the adjustment, and the mobile station receives the broadcast signal to thereby adjust the frame of the next frame. A wireless communication method characterized by estimating timing. 2. When the base station adjusts its own frame timing, the base station transmits a broadcast signal for informing the mobile station connected to the base station of the adjustment amount, and the mobile station receives the broadcast signal, whereby the frame of the next frame is received. A wireless communication method characterized by estimating timing. 3. When the base station adjusts its own frame timing, the base station transmits a broadcast signal informing a mobile station connected to the base station of a direction to adjust the frame timing, and the mobile station receives the broadcast signal. A wireless communication method comprising estimating a frame timing of a next frame. 4. When the base station adjusts its own frame timing, the base station transmits a broadcast signal to notify a mobile station connected to the base station of the direction and the amount of adjustment of the frame timing, and the mobile station receives the broadcast signal. A wireless communication method for estimating a frame timing of a next frame. 5. An adjacent base station frame timing detecting means for generating adjacent base station frame timing information from a received signal from an adjacent base station, and a timing indicating the adjacent base station frame timing information and the transmission timing of a previously transmitted frame signal. Transmission timing control means for generating timing information indicating the transmission timing of the frame signal to be transmitted this time based on the information, and generating timing change information indicating whether or not the transmission timing has been changed; and And a frame signal generating means for generating a frame signal. 6. The base station apparatus according to claim 5, wherein the transmission frame timing control means outputs timing change information indicating a change amount of the transmission timing, instead of the presence / absence of the change of the transmission timing. 7. The base station apparatus according to claim 5, wherein the transmission frame timing control means outputs timing change information indicating a direction of the change of the transmission timing instead of the presence or absence of the change of the transmission timing. 8. The base station according to claim 5, wherein the transmission frame timing control means outputs timing change information indicating the direction and the amount of change of the transmission timing in addition to the presence or absence of the change of the transmission timing. Station equipment. 9. A frame timing control means for estimating a frame timing of a next frame based on timing change information transmitted from the base station apparatus according to claim 5. Mobile station equipment.