KR20100095943A - Method of allocating radio resources in mobile telecommunications system - Google Patents

Abstract

PURPOSE: A method for allocating resources in a mobile communication system is provided to unify encoding processes of data information and a CQI to locate a location of a transmission resource around a pilot signal, thereby simply designing the configuration of a transceiving terminal. CONSTITUTION: A CQI(Channel Quality Indicator), a PMI(Pre-coding Matrix Index) and an RI(Rank Indicator) are encoded. The encoded CQI is allocated to an uplink resource around a pilot channel. Data information and ACK/NACK information are allocated to the uplink resource around the pilot channel. The CQI and the data information are transmitted to a receiver. The ACK/NACK information and the data information are allocated to the left side around the pilot signal. The CQI is allocated in the right side around the pilot signal.

Description

Resource allocation method in mobile communication system {METHOD OF ALLOCATING RADIO RESOURCES IN MOBILE TELECOMMUNICATIONS SYSTEM}

The present invention relates to transmitting channel information in a mobile communication system (wireless communication), and the present invention relates to channel information indicator (CQI, PMI & RI) and resource allocation requester (Scheduling) in the uplink of a long term evolution (LTE) system. Request is encoded together and transmitted to transmit channel information.

The present invention relates to a technique for reducing the probability of reception error at the receiving end and the complexity between transmission and reception by applying channel conditions more effectively when the control information and data information are simultaneously transmitted in the uplink of the LTE system.

1 is a network structure of an LTE system which is a conventional mobile communication system. The LTE system is an evolution from the existing UMTS system.

The LTE network can be roughly divided into an E-UTRAN (Evolved UMTS Terrestrial Radio Access Network) and a CN (Core Network). The E-UTRAN consists of a User Equipment (UE), an Evolved NodeB (eNB), and an Access Gateway (aGW) located at an end of a network and connected to an external network. The aGW may be divided into a part that handles user traffic and a part that handles control traffic. In this case, a new interface may be used to communicate with each other between aGW for processing new user traffic and aGW for controlling traffic. One or more cells may exist in one eNB. An interface for transmitting user traffic or control traffic may be used between eNBs. The CN may be configured as a node for user registration of the aGW and other UEs, and the like. An interface for distinguishing between E-UTRAN and CN may be used.

Meanwhile, a channel communicating between a base station and a terminal is divided into an uplink and a downlink. The downlink is a channel through which the terminal transmits information and data to the base station, and the uplink is a channel through which the terminal transmits information and data to the base station. In order to facilitate communication between the base station and the terminal, it is very important to inform the state of the channel between the terminal and the base station. In particular, this operation is essential in a wireless communication system in which uplink and downlink use different frequency bands. In general, downlink channel information is transmitted through the uplink, and uplink channel information is transmitted through the downlink. In the LTE system, there is an indicator for transmitting downlink channel information to the uplink, which is called a channel information indicator.

There are three types of indicators that inform downlink channel information of the LTE system. Channel Quality Indicator (CQI), which is a channel quality indicator indicating channel quality, Pre-coding Matrix Index (PMI), which is a line coding matrix index that indicates downlink transmission method suitable for channel status and encodes according to channel status. There is a rank indicator RI (Rank Indicator) indicating the transmission method of the downlink. In particular, the channel quality indicator (CQI) is information for informing the quality of the channel between the terminal and the network. Usually, downlink channel information is sent uplink, and uplink channel information is sent downlink. These channel information (CQI, PMI & RI) are indicative of a downlink transmission method, and are transmitted from the terminal to the base station through the uplink.

2 illustrates an uplink transmitted according to channel information. The channel information indicators (CQI, PMI & RI) are transmitted through an independent uplink channel, but if there is data information transmitted on the uplink, the method of transmitting the information is different.

As shown in FIG. 2, when data information is not simultaneously transmitted on the uplink, channel information indicators CQI, PMI, and RI are transmitted upward through an independent control channel. However, when data information is simultaneously transmitted on the uplink, a control channel is not opened. Instead, data information and channel information indicators (CQI, PMI & RI) are transmitted together through a shared channel.

3 illustrates a resource allocation method according to uplink transmission information.

3 shows that data to be transmitted in uplink is allocated to a time axis and a frequency axis. In FIG. 3, a channel tracking signal and a pilot signal (DM-RS) are allocated to each frequency based on a predetermined time when data information is transmitted, and data to be transmitted in uplink are allocated to uplink resources around the DM-RS. do. That is, when only data information is transmitted on the uplink, all transmission resources are occupied by the data information.

Meanwhile, when the channel information indicators CQI, PMI & RI are transmitted on the uplink together with the data information, the channel quality indicator CQI and the line coding matrix index PMI are different from the rank indicator RI in a different way from the data. It is sent mixed. As shown in FIG. 3, when the channel information indicator and the data information transmission occur simultaneously, the channel quality indicator CQI, the line code, the command index PMI, and the rank indicator RI share how data and transmission resources are shared. It shows whether you do.

If the channel information indicators (CQI, PMI & RI) are present, the data information is passed to the channel information indicators (CQI, PMI & RI) part of the used transmission resources.

4 illustrates a method and direction of resource occupancy of channel information indicators (CQI, PMI & RI) in a data channel. 4 illustrates the order and direction in which resources are occupied according to each channel indicator when channel information indicators CQI, PMI & RI are transmitted on the uplink together with data information.

As shown in FIG. 4, the channel information indicators CQI, PMI, and RI use transmission resources differently from the channel quality indicator CQI, the line coding matrix index PMI, and the rank indicator RI. That is, the channel quality indicator (CQI) and the line coding matrix index (PMI) always occupy and use transmission resources together, but occupy in chronological order when occupying transmission resources. The rank indicator (RI), on the other hand, occupies and uses transmission resources in frequency order.

When the conventional channel information indicators (CQI, PMI & RI) and data information are transmitted together on the uplink, there may be the following problem.

First, the size of the data of the rank indicator (RI) compared to the channel quality indicator (CQI) is very small (for example, 1bit or 2bits). Nevertheless, the encoding process of the rank indicator (RI) exists independently, and when transmitted together with the data information, the transmission resources are independently allocated. For this reason, when the channel quality indicator (CQI) and the line coding matrix index (PMI) are present together with the rank indicator (RI), the transmitting and receiving end undergoes independent encoding and decoding processes, and also allocates transmission resources independently. You lose. This allows the transmitting and receiving end to have a complicated configuration.

Second, most of the resources occupied by the channel quality indicator (CQI) and line coding matrix index (PMI) are used to estimate the channel. In addition, most of the resources occupied by the channel quality indicator (CQI) and the line coding matrix index (PMI) are kept at a considerable distance from the pilot signal (DM-RS). As a result, the channel quality indicator CQI and the line coding matrix index PMI far from the pilot signal DM-RS have a high reception error probability at the receiving end.

Accordingly, in order to solve the problems of the prior art, the present invention reduces the complexity of the transmitting and receiving stage when the channel information indicators (CQI, PMI & RI) are transmitted on the uplink simultaneously with the data information. It proposes a resource allocation method to minimize the probability of receiving error.

In order to solve the above problems, the method of allocating resources to a mobile communication system according to the present invention,

Encoding a channel information indicator comprising a rank indicator (RI); Allocating the coded channel information indicator to uplink resources around a pilot channel; Allocating data information and ACK / NACK information to uplink resources around the pilot channel; And transmitting the channel information indicator and the data information to a receiving end.

Preferably, the resource is allocated so that the channel information indicator is arranged on the right side of the pilot signal, and the data information and the ACK / NACK information are allocated on the right side of the pilot signal.

Preferably, the channel information indicator includes at least one channel quality indicator (CQI), a line coding matrix index (PMI), and a rank indicator (RI).

Preferably, in the channel information indicator, the channel quality indicator (CQI), the line coding matrix index (PMI), and the rank indicator (RI) are simultaneously encoded and allocated to uplink resources. .

Advantageously, if said pilot channel is assigned to frequencies of a particular time of the uplink,

The coded channel information indicator, the data information and the ACK / NACK information are allocated to frequencies before and after the specific time with respect to the pilot channel at the specific time.

The present invention unifies the encoding process of the channel information indicators (CQI, PMI & RI) transmitted together with the data information on the uplink, and locates the transmission resource around the pilot signal (DM-RS). The configuration can be simply designed and the effect of reducing the reception error probability can be reduced.

In addition, the present invention, the location of the transmission resources of the ACK / NACK transmitted in response to the downlink data is also located only around the pilot signal (DM-RS), reducing the number of downlink retransmissions mobile communication system (for example, LTE system) has the effect of increasing the overall resource capacity.

The present invention is applied to a mobile communication system such as LTE. However, the present invention is not limited thereto and may be applied to all communication systems and communication protocols to which the technical spirit of the present invention can be applied.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes any item of a plurality of related listed items or a plurality of related listed yields.

When an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may be present in between. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described on the specification, and one or more other features. It is to be understood that the present disclosure does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The description will be omitted.

The basic concept of the present invention is that, in order for the channel information indicators CQI, PMI & RI to transmit data information through the uplink simultaneously, 1) the channel information indicator performs an encoding process simultaneously, and 2) the encoded channel information. The indicator is allocated to uplink resources around the pilot signal, and data information is allocated to the uplink around the pilot signal and transmitted to the receiver. Thus, the present invention is to reduce the complexity of the transmitting and receiving stage, and to minimize the reception error (error) probability at the receiving end.

The most important thing in the wireless communication system is how to estimate the channel to lower the reception error probability. To this end, since information to be transmitted exists around the pilot signal (DM-RS) used for channel estimation, the result of channel estimation should be immediately applied even in a fast channel change to lower the reception error probability. In particular, downlink channel information indicators (CQI, PMI & RI), which determine the channel status and transmission mode of the downlink, should be placed immediately around the pilot signal and thus be applicable immediately as a result of channel estimation.

FIG. 5 illustrates a method of allocating resources of channel information indicators (CQI, PMI & RI) in an uplink channel according to an embodiment of the present invention. FIG. 5 illustrates a method and direction of using transmission resources when channel information indicators (CQI, PMI & RI) are transmitted together with data information on the uplink. In FIG. 5, the numbers indicate the order of use of transmission resources used by each transmission information.

As shown in FIG. 5, unlike the conventional method, it can be confirmed that all channel information indicators CQI, PMI & RI are gathered around a pilot (DM-RS) which is a channel estimation signal.

That is, ACK / NACK information and data information are allocated to the left side based on the pilot signal DM-RS, and channel information indicators CQI, PMI & RI are allocated to the right side.

As such, in order for the channel information indicators CQI, PMI & RI to be allocated together around the pilot signal DM-RS, the channel information indicators CQI, PMI & RI are encoded together and received. At the end (base station or network), decryption must be done together. In this way, the probability of reception error at the receiving end can be lowered and the complexity can be reduced as well.

In addition, the resource allocation of the ACK / NACK information, which is a response to the downlink data, is much simpler than the conventional complex resource allocation, and also includes a pilot, which is a channel estimation signal such as channel information indicators (CQI, PMI & RI). Being next to the DM-RS can reduce the probability of reception errors. This can ultimately reduce the number of downlink retransmissions, resulting in higher efficiency in radio resource utilization.

FIG. 6 is a block diagram illustrating a process of encoding channel information indicators (CQI, PMI & RI) at a transmitting end according to an embodiment of the present invention.

As shown in FIG. 6, in the prior art, the rank indicator RI is encoded independently of the channel quality indicator CQI and the line coding matrix index PMI, and resources are allocated independently to the uplink. . However, in the present invention, the channel information indicator including the rank indicator (RI) is integrated at a time so that the encoding process is performed, and resources are allocated to uplink. In addition, all the channel information indicators CQI, PMI, and RI, which are encoded in this way and allocated resources in the uplink, are transmitted on the uplink together with the data information.

On the other hand, the method according to the invention described so far may be implemented in software, hardware, or a combination thereof. For example, the method according to the present invention may be stored in a storage medium (eg, mobile terminal internal memory, flash memory, hard disk, etc.) and may be stored in a processor (eg, mobile terminal internal microprocessor). It may be implemented as codes or instructions in a software program that can be executed by.

In the above, the present invention has been described with reference to the embodiments shown in the drawings, which are merely exemplary, and those skilled in the art may understand that various modifications and equivalent other embodiments are possible. will be. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a network structure of an LTE system which is a conventional mobile communication system. The LTE system is an evolution from the existing UMTS system.

2 illustrates an uplink transmitted according to channel information.

3 illustrates a resource allocation method according to uplink transmission information.

4 illustrates a method and direction of resource occupancy of channel information indicators (CQI, PMI & RI) in a data channel.

FIG. 5 illustrates a method of allocating resources of channel information indicators (CQI, PMI & RI) in an uplink channel according to an embodiment of the present invention.

FIG. 6 is a block diagram illustrating a process of encoding channel information indicators (CQI, PMI & RI) at a transmitting end according to an embodiment of the present invention.

Claims (5)

Encoding a channel information indicator including a rank indicator (RI); Allocating the coded channel information indicator to uplink resources around a pilot channel; Allocating data information and ACK / NACK information to uplink resources around the pilot channel; And transmitting the channel information indicator and the data information to a receiving end. The method of claim 1, Allocate resources so that the channel information indicator is placed on the right side of the pilot signal, And allocating the data information and the ACK / NACK information to the right side of the pilot signal. The method of claim 1, wherein the channel information indicator is And at least one channel quality indicator (CQI), a line coding matrix index (PMI), and a rank indicator (RI). 4. The method of claim 3, wherein in the channel information indicator A channel quality indicator (CQI), a line coding matrix index (PMI), and a rank indicator (RI) are simultaneously encoded and allocated to uplink resources. The method of claim 1, If the pilot channel is assigned to frequencies of a particular time of the uplink, And assigning the coded channel information indicator, the data information, and the ACK / NACK information to frequencies before and after the specific time, for the pilot channel at the specific time. Way.

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