KR20080020395A - Method of controlling signals transmission and reception in mobile communication system - Google Patents

Abstract

A method for controlling signal transceiving timing in a mobile communication system is provided to control timing for transmitting signal according to the receiving timing offset of a corresponding BS, thereby effectively diversifying interference between cells in a cellular mobile communication system. A BS(Base Station) sets timing offset for the reception of a signal transmitted from a UE(User Equipment)(S31). The BS transmits a specific signal to the UE and receives a response signal for the transmitted signal(S32,S33). The BS calculates round trip delay(S34). The BS transmits ATV(Advance Time Value) in the UE according to the calculated round trip delay(S35). The UE controls signal transmission timing by using the ATV transmitted from the BS(S36).

Description

Method of controlling signal transmission and reception timing in mobile communication system {Method of controlling signals transmission and reception in mobile communication system}

1 is a view for explaining a signal transmission and reception method in a cellular mobile communication system according to the prior art.

2 illustrates an example of an uplink packet structure used in an LTE system.

3 is a process flow diagram according to one preferred embodiment of the present invention.

4 is a view for explaining another preferred embodiment of the present invention.

The present invention relates to a cellular mobile communication system. More specifically, the present invention relates to a method for controlling signal transmission and reception timing in a cellular mobile communication system.

1 is a view for explaining a signal transmission and reception method in a cellular mobile communication system according to the prior art.

In a cellular mobile communication system, a user equipment (UE) obtains timing information based on a synchronization signal transmitted from a base station (BS). For example, in a long term evolution (LTE) system, a UE acquires timing information through a synchronization channel (SCH). The UE transmits a bottom-up access signal and data based on the obtained timing information to access the base station. However, a signal transmitted and received between the UE and the base station generates a delay, as shown in FIG. 1. That is, the signal transmitted from the base station arrives delayed to the UE due to the distance between the base station and the UE, the effect of the channel, and similarly, the signal transmitted from the UE to the base station also arrives delayed to the base station based on the received signal.

As described above, the delay in which the base station transmits a signal to the UE and the response signal transmitted by the UE in response to the received signal reaches the base station is called a round trip delay. The base station calculates the round trip delay time based on the signal received from the UE and informs the UE of an Advance Time Value (ATV). In addition, the base station continuously delivers the ATV to all connected UEs to control the arrival signal timings from all the UEs to be matched, and the timing matched in this manner is called system time. The reason for this continuous timing control is when resources are allocated in time (ex. Packet data network, UL and DL in TDD system), if the timing control is not done properly, the resources in the transition period of resource allocation Will cause a crash. For example, when allocating resources to each UE in a very small time (0.5 ms) unit, such as LTE system, this problem is very fatal.

2 illustrates an example of an uplink packet structure used in an LTE system. Various information (eg, control channel (CQICH, ACKCH), pilot channel, data channel) may be transmitted in one packet. Such information may be multiplexed and transmitted in various ways. FIG. 2 illustrates an example of multiplexing in a TDM manner.

In a cellular mobile communication system having a synchronous network structure, when all base stations control the same timing of arrival signals from all UEs according to the same reception timing criteria as described above, interference may occur within a specific time zone. Different characteristics may be exhibited, and in some cases, interference may be concentrated at a time timing at which main information such as control information is concentrated. For example, in the LTE system, a control channel is transmitted simultaneously by multiple UEs, and a data channel is transmitted by one or two UEs in one resource block (RB). In the case of SB1, a CQ pilot and a DM pilot are multiplexed and transmitted. Therefore, when power control is performed while watching a control channel or a pilot channel, interference generated between base stations has a different characteristic in time, which may have an undesirable effect on power control. In addition, when the control channel and the data channel have different interference characteristics, system optimization becomes very difficult.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention is to provide a method for effectively controlling the inter-cell interference in a cellular mobile communication system.

Another object of the present invention is to provide a method for controlling signal transmission / reception timing in a cellular mobile communication system.

In one aspect of the present invention, a method of controlling signal reception timing according to the present invention is that in a cellular mobile communication system, different timing offsets for receiving signals from a terminal are set for at least two base stations. It features.

According to another aspect of the present invention, there is provided a method of controlling signal reception timing according to the present invention, the method comprising: setting different timing offsets for signal reception from a terminal for at least two or more base stations; And controlling the signal reception timing from the terminal according to the offset.

In another aspect of the present invention, a timing control method for signal transmission according to the present invention is a timing control method for signal transmission in a specific terminal of a cellular mobile communication system, the timing offset information configured for signal reception from a base station And receiving a signal and controlling signal transmission timing by using the timing offset information.

The construction, operation, and other features of the present invention will be readily understood by the preferred embodiments of the present invention described below with reference to the accompanying drawings.

3 is a process flow diagram according to one preferred embodiment of the present invention. Referring to FIG. 3, a timing offset for receiving a signal transmitted from the terminal UE is set in the base station BS [S31]. The timing offset provides reference time information necessary for controlling the arrival timing of the signals transmitted from the terminals in the cell to be consistent. In this case, the reception timing offset is set differently between neighboring base stations. Preferably, the timing offset between neighboring base stations is set to have a random characteristic. Setting of a reception timing offset for each base station on the system may be performed at or after network design.

The base station transmits a specific signal to the terminal [S32], and receives a response signal to the transmitted signal from the terminal [S33]. The base station calculates a round trip delay from a time when the base station transmits a signal to the terminal and a time when the response signal is received from the terminal [S34]. The base station transmits an Advance Time Value (ATV) from the terminal according to the calculated round trip delay [S35]. The ATV is a value to be corrected when the terminal transmits a signal in order to reduce the round trip delay, and may have a positive value or a negative value and may be expressed as an absolute value. The base station transmits the ATV to all the connected terminals in the cell so that the signal transmitted from each terminal can be received at the same time. The terminal controls the signal transmission timing using the ATV transmitted from the base station [S36].

FIG. 4 is a diagram illustrating another exemplary embodiment of the present invention, and illustrates a process of performing handover between base stations BS1 and BS2 having different reception timing offsets.

In a system in which neighboring cells each have a different time reference for receiving a signal from a terminal, that is, a different cell-specific timing offset, the terminal is handed from a source BS to a target BS. This can be problematic because the target base station signal transmission and reception timing cannot be predicted when attempting to over. Therefore, the reception timing offset of the base station should be known to all terminals. The reception timing offset may be notified through broadcast, multicast, or dedicated signaling for a specific terminal. Through the above method, the UE acquires a reception timing offset of the target base station and transmits a signal to the target base station using the reception timing offset. For example, as shown in FIG. 3, when performing a handover to the source base station BS2 during communication with the target base station BS1 at the time of handover, an attempt is made to access to the target base station or traffic ( traffic). In this case, it is necessary to perform timing control for signal transmission by the terminal itself before it is stabilized by receiving timing control from a target base station. That is, the terminal may transmit a signal to the target base station after adjusting a transmission timing set for communication with the source base station by using a difference t2-t1 of a reception timing offset between the source base station and the target base station. have.

In another embodiment of the present invention, the terminal may perform timing control for signal transmission according to a reception timing offset of the corresponding base station even in an initial access process. That is, in a cellular mobile communication system in which different reception timing offsets are set for each base station, when the terminal performs an initial access procedure to a specific base station, the terminal receives the reception timing offset information of the base station from the base station and accordingly to the base station. The signal is transmitted after controlling the transmission timing for signal transmission.

It is apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

According to the present invention, it is possible to control signal transmission / reception timing in a system so as to effectively distribute interference between cells in a cellular mobile communication system.

Claims (5)

In a cellular mobile communication system, Signal timing control method characterized in that different timing offset (timing offset) for receiving a signal from the terminal is set for at least two base stations. In a cellular mobile communication system, Setting different timing offsets for signal reception from a terminal for at least two base stations; And And controlling the signal reception timing from the terminal according to the set timing offset in the at least two base stations. The method of claim 2, And a timing offset set in the at least two base stations is randomly set. A timing control method for signal transmission in a specific terminal of a cellular mobile communication system, Receiving timing offset information set for signal reception from a base station; And And controlling signal transmission timing by using the timing offset information. The method of claim 4, wherein The timing offset is a timing control method for signal transmission, characterized in that randomly set for each base station.

Images