JPH02200018A - Diversity branch switching control system - Google Patents

Abstract

PURPOSE:To obtain a transmitting/receiving antenna switching diversity by signals, transmitting from a transmission station with adding an identifier, and storing the information of an optimal branch from signals received by means of a receiving station, and transmitting a packet with adding the optimal branch identifier. CONSTITUTION:A base station (a) transmits a first packet from the branch selected while adding the branch identifier, and transmits a second packet by selecting the different branch while adding the branch identifier. On the other hand, a mobile station (b) is composed so as to store the received larger level branch for the packet transmitted from the different branches, when the mobile station transmits the information, the stored branch information is transmitted by adding it to the packet as the optimal branch identifier. In the base station, transmitting antennas 9a and 9b for the mobile station are controlled by the optimal branch identifier sent from the mobile station. Thus the same effect as the execution of the receiving diversity for the both stations can be obtained in simple constitution.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a method for easily configuring guiversity, which is an effective means for reducing the influence of 7-enong, which is a major cause of characteristic deterioration, in the field of wireless communication. This relates to a control method.

[Conventional technology]

Generally, in the field of wireless communication, the occurrence of aging, which is caused by the so-called multipath radio wave propagation between a transmitting point and a receiving point, is a major cause of characteristic deterioration.

Especially in mobile communications, j! It is known that the IkIi station is in motion (and that a LeRae-7 A song accompanied by severe level fluctuations occurs).

Guiversity is an effective technology to overcome the deterioration of communication conditions due to aging.

Guiversity is a signal reception system in which two or more propagation paths are provided between a transmitting point and a receiving point so that the 7 ahnongs generated in each propagation path are independent, and the same information is transmitted and received through these propagation paths. This is an attempt to improve the reliability of time.

Therefore, a transmitting/receiving device for performing ubiquity generally has a configuration that allows redundancy. There are various configuration methods for diversity, but antenna switching diversity is the configuration method with the smallest physical redundancy.

An example of the configuration of an antenna switching dive branch is shown in FIG.

In Figure 1, in and lb are antennas, 2 is a switch,
3 represents a receiver or transmitter, and 4 represents a control section.

In such a diversity system, in particular, by using a transmitting diversity branch and a receiving branch branch that switch transmitting antennas together, it is possible to configure only one radio station to be equipped with a diversity device. The configuration in which the device is installed is
This is an effective means for downsizing mobile stations.

However, in this case, an auxiliary means for selecting a diversity branch is required on the mobile station side to control switching of the transmitting antenna branches of the base station.

For this reason, it is also called feedback guidance.

[Problems to be Solved by the Invention] As mentioned above, it is effective to use both transmitting and receiving guiversity on one wireless station side;
In order to perform transmit diversity, it is necessary to inform (feedback) information regarding branch selection that can only be obtained on the receiving station side to the transmitting side that performs transmit antenna switching by some means.

Conventionally, an out-of-band tone or the like has been used as a branch switching control means for this feedback diversity.
This resulted in the complexity of the equipment on the mobile station side.

SUMMARY OF THE INVENTION An object of the present invention is to provide a system that can perform transmission and reception antenna switching variably with an extremely simple configuration in order to solve the above-mentioned problems.

[Means to solve the problem]

According to the invention, the above objects are achieved by the means specified in the claims.

That is, the present invention provides a wireless communication method in which the transmitting station performs guiversity in which the optimal transmitting antenna is selected for each transmitting packet, and when transmitting the transmitting bucket F to the transmitting station,
Providing means for adding an identifier for identifying the selected branch to the transmitted packet, and also providing means for storing the identifier with the highest reception level in the receiving station, and means for notifying the other transmitting station of the stored identifier, This is a diversity branch switching control method in which a transmitting station selects a transmitting antenna based on an R identifier notified from a receiving station.

[For production]

In the branch switching control method according to the present invention, a transmitting station adds a branch identifier indicating the transmitting antenna and transmits the signal, and a receiving station stores information on the optimal branch from the received signal, and the transmitting station switches the transmitting antenna. The optimal branch identifier is added to the packet for transmission.

Thereby, the transmitting station that performs transmission antenna switching can select the optimal transmission branch for the receiving station based on the optimal branch identifier added to the packet 7) transmitted from the partner receiving station.

〔Example〕

FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and shows an example in which the present invention is applied to mobile communication, in which (a) shows the configuration of a base station, and (b) shows the configuration of a mobile station. It represents.

In the same figure, 5, 14, 19.27 are baseband,
6 and 20 are modulators, 7.21 is a transmitter, 8 and 17 are switchers, 9a, 9b, and 22 are transmitting antennas, 10.23 is an identifier adding section, 11 is a control section, and 12.25 is a level detection section , 1326 is an identifier determination unit, 15.28 is a demodulator, 16
．． 30 is a receiver, 18a, 18b, 29 are receiving antennas, and 24 is a storage unit.

Among the above parts, numbers 5 to 9, 14 to 18 and 19
~22. The devices shown in 27 to 29 are similar to conventionally used general transmitting/receiving devices, but 10 to 13
, and 23 to 26 are devices added according to the present invention.

At the base station, the first packet to be transmitted is added with a branch identifier indicating which branch to transmit from, and transmitted from the selected branch.For the second packet to be transmitted next, a different branch is selected. , and send it with that branch identifier.

On the other hand, the mobile station is configured to compare the received levels of packets transmitted from different branches and store the branch with the higher level, and when the mobile station transmits, it uses the stored branch information as the optimal branch identifier to add the packet to the packet. Add and send.

Furthermore, the base station controls the transmitting antenna for the mobile station based on the optimal branch identifier sent from the mobile station.

FIG. 3 is a diagram showing an example of the radio channel configuration of the TDMA1FDD system, in which (a) shows the frame structure, (b) shows the downlink, and (C) shows the uplink.

In the same figure, 31 is TDMA 17 frames, 32.3
4a, 34b are control stands 07, 33m-33c, 3
5a and 3Sb represent telephone number 02, and
The letter B represents a branch identifier within the control slot 32.

For example, in a TDMA/FDD radio channel configuration as shown in Figure 3, performing transmission and reception diversity at the base station is equivalent to performing reception diversity between the mobile station and the base station. The effect of this can be obtained.

In other words, in one frame, the downlink consists of a control slot and a speech slot, and the uplink slot consists of a speech slot, and the downlink control slot is used to broadcast information such as base station information to the mobile station at regular intervals. It is assumed that a signal is transmitted, and the transmitting antenna is turned off each time a broadcast signal is transmitted. At this time, as shown in FIG. 3, each packet transmitted on the downlink is transmitted with a branch identifier indicating the selected branch added thereto.

Since the mobile station constantly receives this broadcast signal during standby, it is possible to compare the respective reception levels and know and store the optimal branch.

The mobile station sends an optimal branch identifier to the base station by adding an optimal branch identifier based on stored information to the calling signal when making a call, and to the incoming call response signal when receiving a call. It is possible to notify.

For example, when a mobile station receives a call and slot 2 is indicated by the alphabet C,
is specified, the mobile station adds an optimal branch identifier to a packet containing an incoming call response signal to be transmitted in slot 2, and transmits the packet.

Thereafter, the base station may select the branch notified to the mobile station and communicate with the mobile station.

Furthermore, during communication, the mobile station can receive both the broadcast slot and the call slot in the TDMA 7 frames, and by receiving the broadcast slot even during the call, it is possible to detect that the branch of the call slot is not optimal. It is also possible to detect. In such a case, it is also possible to request the base station to reselect the branch.

When the above control is performed, it is also applicable to radio channel configurations other than the FDD method.

According to the present invention, for example, when the number of branches M = 2.17 frame length is τpr = 8 m5ee s, and the control time until switching to another branch after detecting deterioration of a branch in use is Tc = 2XτF = 16 asee, the present invention Figure MS4 shows a comparison of the effects of the invention with no diversity and selection diversity.

In the figure, the horizontal axis is the ratio (dB) of the average reception level to the threshold Rs, and the vertical axis is the frame non-reception rate.

From FIG. 4, it can be seen that the effect is greater when the reception level b0 is smaller than the threshold value Rs.

In addition, the effect of the present invention is large when the seven-way pitch Fd is sufficiently small, so if the moving speed is sufficiently slow or the mobile phone hardly moves, such as a cordless telephone, an effect similar to that of selection variability can be obtained. Obtainable.

In the above description, the case of a mobile communication system is explained as an example, but the present invention is not limited to mobile communication, but can also be applied to communication between fixed stations.

〔Effect of the invention〕

As described above, according to the present invention, the branch identifier transmitted from the receiving station makes it possible to perform transmission diversity at the partner transmitting station, and furthermore, the station that performs transmit antenna switching can perform the conventional reception diversity. By doing so, it is possible to obtain the same effect as performing reception diversity on both sides with a very simple configuration in which the antenna of only one wireless device is switched. Particularly when applied to mobile communications, there is an advantage that mobile stations can be made smaller and more economical without sacrificing communication quality.

Furthermore, since the control is shared between the base station and the mobile station, there is an advantage that the load on the control CPU can be distributed.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the configuration of a conventional antenna switching diversity, FIG. 2 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 3 is an example of a TDMA/FDD channel configuration according to the embodiment. FIG. 4 is a characteristic diagram showing a comparison of the frame non-receiving rate with the case of selection diversity, etc., in order to explain the present invention in detail. 1a, 1b...Antenna, 2.
...Switcher, 3 ...4 ...Control section, 27 ...Baseband, ...Modulator, 7 8.17 ...・Switcher, 22...Transmission antenna,...Identifier addition section, Control section, 12 Detection section, Judgment section, 16 30...18b, 29...・ 24... Storage unit, A17 frame,... Control slot, 35a, 35b -- 13, 26... Identifier 15 28... Receiver, Receiver , 18a. Receiving antenna, 31...TDM 32.34a, 34b-33a to 33c. Call slot receiver or M transmitter, 6 20...21...Transmitter, 9a, 9b. １１・・・・・・System ２５・・・・・・Level 3rd figure

Claims (1)

[Claims] In a wireless communication system that performs diversity in which a transmitting station selects an optimal transmitting antenna for each transmitted packet, when transmitting a transmitting packet to the transmitting station, an identifier for identifying the selected branch is added to the transmitted packet. In addition, the receiving station is provided with means for storing the identifier with the highest reception level, and means for notifying the other transmitting station of the stored identifier, and the transmitting station receives the identifier based on the identifier notified from the receiving station. A diversity branch switching control method characterized in that a transmitting antenna is selected based on the selected transmitting antenna.