KR100868494B1 - Apparatus and method for transmitting/receiving feedback information in multi-user multiple transceiving antenna communications and system thereof - Google Patents

Abstract

The present invention proposes a transmission and reception apparatus and method for transmitting and receiving feedback information in a multi-user multi-antenna system for reducing the amount of feedback information transmitted from a receiver, and a system thereof.

To this end, the present invention in the multiple transmit and receive antenna system, the transmitter determines a reference CQI and transmits to the receiver. When the receiver receives the reference CQI, the received reference CQI is compared with the magnitude of the CQI of the stream received from the transmitter, and the channel on which the stream is received is set as active or inactive according to the comparison result. In addition, since the set channel state information is transmitted to the transmitter, even if the receiver receives a plurality of streams from the transmitter, only the active or inactive information of the channel for each stream is transmitted to the transmitter, thereby reducing the amount of system-wide feedback. have.

Multi-user multi-antenna system, feedback information, channel quality

Description

Transmitting and receiving apparatus and method for transmitting and receiving feedback information in a multi-user multi-receiving antenna system and a system thereof

1 is a configuration diagram of a multi-user multiple transmit / receive antenna system according to an embodiment of the present invention.

2 is a flowchart illustrating a feedback method of a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

3 is a block diagram illustrating an embodiment of an active / inactive switching feedback scheme in a multi-user multiple transmit / receive antenna system according to an embodiment of the present invention.

4 is a block diagram illustrating an apparatus for receiving feedback information of a transmitter in a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

5 is a flowchart illustrating a method for transmitting and receiving feedback information of a transmitter in a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

6 is a block diagram illustrating a feedback transmitter of a receiver in a multi-user multiple transmit / receive antenna system according to an embodiment of the present invention.

7A and 7B are flowcharts illustrating a method for transmitting and receiving feedback information of a receiver in a multi-user multiple transmit / receive antenna system according to an embodiment of the present invention.

The present invention relates to a multiple transmit and receive antenna system and a method thereof, and more particularly, to a transmitting and receiving device and method for transmitting and receiving feedback information in a multi-user multi transmit and receive antenna system to reduce the amount of feedback information transmitted from a plurality of receivers. .

Generally, the 3G system (beyond the 3G system), that is, the 4th generation system, is characterized by Ubiquitous & Seamless connection, High data rate, Openness, and network convergence in both a wireless network and a core network. Say In addition, these fourth generation systems are designed to enable high-capacity data transmission with a focus on high data rates.

This fourth generation system should have a complex form, not a single network. In other words, the satellite network, wireless LAN, digital audio broadcast (DAB), digital video broadcast (Digital Video Broadcast, DVB) network, etc. should all be integrated. As such, when all networks are integrated, data or signals may be transmitted and received between multiple transceivers (eg, base stations and terminals) at the same time using multiple input multiple output (MIMO). Such a multi-user multiple transmit / receive antenna system arranges M times antennas in a transmitter (eg, a base station) and N antennas in receivers. As such, when a signal is transmitted and received using the arrayed antennas, an increase in data rate may be achieved.

As such, in order to provide a multi-user multi-antenna service through a plurality of antennas provided in the transceivers, a transmitter needs channel quality information (CQI) of a plurality of receivers. Therefore, the transmitter requests feedback information including CQI from a plurality of receivers. In addition, the transmitter requires a larger amount of CQI to multiple receivers in order to use a multi-carrier technology or a multiple antenna technology.

However, such a large amount of feedback information not only increases the throughput of the transceiver but also requires a lot of resources, which in turn degrades the overall system performance. In order to overcome this problem, a method of feeding back a CQI to only a user having a CQI higher than a predetermined threshold has been proposed in the related art. However, since only a user with a relatively good channel condition gives a CQI feedback, the feedback overhead can be somewhat reduced. There is still a problem of feedback overhead because the CQI is fed back as it is.

Accordingly, in view of the foregoing, the present invention proposes a transmission and reception apparatus and method and system for transmitting and receiving feedback information in a multi-user multi-reception antenna system that increases system performance by reducing the amount of feedback information.

The apparatus and method for transmitting and receiving channel quality information according to the present invention propose a method of feeding back a CQI with only 1 bit per channel.

In addition, the present invention proposes a transmitter for determining a reference CQI and a feedback information receiving apparatus and method for the transmitter when the statistical distribution of the CQI is known and unknown using the CQI received from a plurality of receivers.

In addition, the present invention proposes a receiver for setting the active or inactive of a corresponding channel and a feedback information transmitting apparatus and method of the receiver compared to the CQI of the stream received using the reference CQI received from the transmitter.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. In addition, terms to be described below are terms defined in consideration of functions in the present invention, and may be changed according to a user, a user's intention or custom. Therefore, the definition should be made based on the contents throughout the specification.

In the following detailed description of the present invention, a multi-user multiple transmit / receive antenna system for improving system performance by reducing the amount of feedback information proposed by the present invention will be described, and also if the statistical distribution of CQI is known and unknown. A transmitter for determining a reference CQI and a method thereof will be described. Also, the reference CQI received from the transmitter is used to set the active or inactive of the corresponding channel in comparison with the CQI of the received stream, and the set channel state information is transmitted. We will describe the receiver and the method of following.

The transmitter of the multiple transmit / receive antenna system according to the present invention for achieving the above-mentioned, if the channel state information is received from the receiver after transmitting the reference channel quality information (CQI) to the receiver, the receiver through the received information And a channel state grasping unit to grasp a channel state of the control unit, and a control unit to control beamforming of a plurality of antennas using the identified channel state.

In addition, the method for receiving feedback information of a transmitter in a multiple transmit / receive antenna system according to the present invention for achieving the above-mentioned, the process of determining a reference CQI to be applied to multiple channels of the receiver, and transmitting the determined reference CQI to the receiver And receiving state information of the channel from the receiver.

In addition, in the multiple transmit / receive antenna system according to the present invention for achieving the above, the receiver comprises a channel quality measurement unit for measuring the CQI (Channel Quality Information) of each stream received from the transmitter, the CQI of the stream and the transmitter And a control unit for comparing the size of the received reference CQI, and setting a corresponding channel according to the comparison result, and a transmitter for transmitting the comparison result to a transmitter.

In addition, the method for transmitting feedback information of a receiver in a multiple transmit / receive antenna system according to the present invention for achieving the above, the process of receiving a reference CQI from the transmitter, the received reference CQI and the CQI of the stream received from the transmitter And comparing and generating channel state information according to the comparison result and transmitting the generated channel state information to the transmitter.

1 is a configuration diagram of a multi-user multiple transmit / receive antenna system according to an embodiment of the present invention.

Referring to FIG. 1, a multi-user multi-transmission / reception system according to an embodiment of the present invention includes a transmitter 100 (eg, a base station) and a plurality of receivers 200 and 300.

The transmitter includes a user selector 150 and a unitary beamforming unit 160. The transmitter 100 performs a precoding process on a plurality of input user data (User1, User2, ..., Userk) and broadcasts the data on which the precoding process has been performed through a plurality of antennas. In addition, the receiver also receives data stored through a plurality of receive antennas, and stores or reproduces the data.

As such, the transmitter provides a multi-user multi-antenna service between the transceivers in the system and broadcasts a reference CQI to multiple receivers to reduce the amount of feedback information. The reference CQI is a threshold used to apply the channel of the receiver as active or inactive. Each receiver receiving the reference CQI compares the received reference CQI with a CQI of a channel corresponding to a stream received thereafter, and sets the corresponding channel as active / inactive and generates an active / inactive (ie, on / off) signal. Transmit to the transmitter. The active signal means when the CQI of the communication channel is greater than or equal to the reference CQI, and the inactive signal means when the CQI of the communication channel is smaller than the reference CQI.

The transmitter, which receives the active / inactive signal from multiple receivers, generates a channel matrix based on the received active / inactive signal, and transmits a stream to the plurality of receivers through the generated channel matrix.

In order to perform this operation, the transmitter must set the reference CQI appropriately for the system environment. Setting methods can be divided into a case where the statistical distribution of the CQI is known and a case where the CQI is unknown. These methods (A or B method) will be described below.

The transmitter can also group multiple receivers according to CQI. That is, since the receivers are located in the outer region or the shadow area of the cell, receivers having poor CQI may be grouped or receivers having good CQI may be grouped.

2 is a flowchart illustrating a feedback method of a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 2, first, a transmitter and a receiver are provided with a plurality of antennas, and multiple input / output services are provided through the provided antennas. As described above, in the multi-antenna system including a transceiver having a plurality of antennas, the transmitter transmits a plurality of streams to the receiver (S100). The transmitted stream is transmitted to the receiver via one or more antennas or to the receiver via one antenna.

As such, when a plurality of streams are received from the transmitter, the receiver feeds back feedback information including the quality of the channel corresponding to the stream having the best channel gain among the received streams (S102). The feedback information includes index information of the stream having the best quality among the plurality of streams and the CQI at that time.

Thereafter, the transmitter transmits a reference CQI to all receivers in the cell (S104). The reference CQI is channel quality information that can be measured or determined by a transmitter or a receiver for smooth transmission and reception between transceivers, or can be flexibly set for system performance. This reference CQI value may be applied to all receivers in common or may be applied to each receiver or grouped receivers. As such, a technique of determining a reference CQI value applied to all receivers or each receiver or grouped receivers will be described below. The receiver receiving the reference CQI in step S104 compares the received reference CQI with the CQI of the communication channel through a stream received for each antenna provided in the receiver (S106). The CQI of the antenna-specific communication channel may be measured through a pilot signal periodically transmitted by the transmitter or may be measured through a stream received from the transmitter. As such, the receiver measuring the CQI of the communication channel for each antenna may periodically measure the channel quality for each antenna provided in the receiver.

When the received reference CQI and the CQI of the channel corresponding to the stream received for each antenna are compared in the step S106, the channel state is set according to the comparison result (S108). Setting the channel state means setting the activation / deactivation of the transmission / reception channel according to the comparison result. The setting of the active means a process for performing communication by connecting a channel of a transmitter and a corresponding antenna, and the setting of inactive means disabling a channel of a transmitter and a corresponding antenna to disable communication, or It means that the reference CQI is set to the CQI of the corresponding stream.

That is, activity indicates that the stream can be used as the preset CQI value because the CQI value of the stream is greater than or equal to the preset CQI value. Inactive indicates that the CQI value of the corresponding stream is smaller than the preset CQI value and thus cannot be used as the preset CQI value, or indicates that the stream cannot participate in scheduling the stream. For example, if the CQI value of a given stream is a natural number larger than the reference CQI (that is, if the integer value is equal to the reference CQI but is larger than the reference CQI by a decimal value), the natural number from which the decimal value is removed (ie, the reference CQI and Set the same integer) to the CQI of the stream.

As such, if the CQI of the communication channel is greater than or equal to the reference CQI, set the channel state to active. However, if the CQI of the communication channel is less than the reference CQI, then set the channel state to inactive.

When the process (S108) is performed, the receiver transmits an active / inactive signal indicating the set channel state to the transmitter (S110). The active / inactive signal may be one according to the receiver or may be as many as the number of antennas according to the channel state of the antenna provided in the receiver. The active / inactive signal is 1 bit in size.

When an active / inactive signal is received from multiple receivers, the transmitter transmits the stream to one or more receivers using a channel corresponding to the received active / inactive signal.

3 is a block diagram illustrating an embodiment of an active / inactive switching feedback scheme in a multi-user multiple transmit / receive antenna system according to an embodiment of the present invention.

Referring to FIG. 3, a receiver receives a number of streams from a transmitter. Then, the stream having the maximum CQI is identified among the received streams. As shown, assume that the CQI of the first stream is 1.5, the CQI of the second stream is 4, the CQI of the third stream is 2.5 and the CQI of the fourth stream is 2. The highest CQI (ie, 4) among the received CQI values is transmitted to the base station. Then, when the reference CQI determined through a plurality of techniques is received from the transmitter, the receiver compares the received CQIs with the CQIs of the multiple streams. Then, the active / inactive signal according to the comparison result is transmitted to the transmitter. That is, as shown, an inactive signal is transmitted to the transmitter for the first stream having a CQI of 1.5, an active signal is transmitted to the transmitter for the third stream having a CQI of 2.5, and an active signal is transmitted for the fourth stream having a CQI of 2. Send to the transmitter. As described above, the multi-user multiple transmit / receive antenna system and the switching feedback technique for reducing the amount of feedback information have been described, and the transceiver applied to the system is described below.

4 is a block diagram illustrating an apparatus for receiving feedback information of a transmitter in a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, as shown in FIG. 4, the transmitter receives a CQI from a plurality of receivers to determine a channel state for each receiver, and according to the identified channel state, through a multiple antenna. A control unit 120 for controlling precoding and multiple outputs of the streams, a coding and modulation unit 130 for coding and modulating a plurality of streams, and a multiple output for multiplexing the plurality of encoded and modulated streams through a plurality of antennas It is composed of a portion 140.

The present invention also includes a memory (not shown) for storing reference CQIs for application to multiple receivers and for storing channel state information received from multiple receivers. The controller 120 is provided with a module for determining a reference CQI through a method such as A or B described below. The reference CQI is transmitted to the receiver.

First, the transmitter sets the reference CQI value through any one of the two methods (A or B method) described below.

There are two methods of determining the reference CQI by the transmitter: when the statistical distribution of the CQI is known and when it is not known (the embodiments of A and B).

A. Knowing the statistical distribution of CQI

If the statistical distribution of the CQI is known, the transmitter may determine the reference CQI using Equation 1 below.

In Equation 1, CQI _reference represents a reference CQI, and α represents a probability of determining a given CQI as active. That is, the transmitter may set the given CQI as active by adjusting the probability α. For example, in Equation 1, α = 0.7 means that the ratio of CQI that is equal to or greater than the _reference CQI (ie, CQI _reference ) among all CQIs is set to 70%. As such, by adjusting the probability α, the transmitter can determine a reference CQI.

This value may be influenced by the number of users or the number of antennas of the respective receivers. That is, when the number of users is small, setting the reference CQI value to a small value by setting the value large, and setting the reference CQI value by setting the value to a small value when the number of users is large may increase the performance of the system. As such, the value is adjustable. As such, by setting the reference CQI small, the transmitter may perform communication with multiple users or multiple antennas.

B. You do not know the statistical distribution of CQI

If the transmitter does not know the statistical distribution of the CQI, the reference CQI may be adjusted using the activity ratio received from users or multiple antennas. For example, if the activity rate received from the users is high, the reference CQI value is increased. On the contrary, if the activity rate is low, the reference CQI value is lowered to increase the performance of the system.

Equation 2 is an equation that can be applied to adjust the reference CQI value over time when the transmitter does not know the statistical distribution of the CQI.

는 시간 t에 사용할 기준 CQI를 나타내고,

은 시스템이 목표로 하는 활성 비율을 나타내고,

는 시간 t에 실제 사용자들이 보고한 활성 비율을 나타낸다. 그리고,

는 시간에 따라 기준 CQI의 변화폭을 결정하는 상수이다. Using Equation 2, a reference CQI to be used at a specific time (that is, t + 1 time) can be calculated. In Equation 2

Represents the reference CQI to use at time t,

Represents the active rate the system is targeting,

Represents the percentage of activity reported by real users at time t. And,

Is a constant that determines the variation of the reference CQI over time.

Using Equation 2, even if the receiver does not know the statistical distribution of the CQI, it is possible to achieve the target activity ratio of the system at a specific time.

After the reference CQI is determined through the above method, the controller 120 transmits the reference CQI to the receiver.

Then, the stream is transmitted to the receiver, and the receiver transmits the CQI of each stream to the transmitter through the received stream. The channel state determiner 110 provided in the transmitter receives the CQI for each stream from the receiver. The CQI is received from a plurality of receivers, and includes information on channel establishment through each stream received by each receiver. That is, the CQI is On information indicating that the channel is set to active and Off information indicating that the channel is set to inactive.

As such, when the information indicating the activation or deactivation of the channel state is received, the channel state of the plurality of antennas provided in the receiver is determined. Then, the determined result is transmitted to the control unit 120. The controller 120 controls transmission of a plurality of streams. That is, the control unit 120 precodes the input multiple streams and generates a channel matrix through active or inactive signals received from the multiple receivers in order to transmit the multiple input streams to the multiple receivers. In addition, the control unit 120 forms a beam of an antenna provided in the transmitter to transmit the precoded streams through the multiple output unit 140 to a plurality of receivers. Then, the stream is transmitted to the plurality of receivers through the beamed antenna.

5 is a flowchart illustrating a method for transmitting and receiving feedback information of a transmitter in a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 5, it is assumed that a transmitter has a CQI threshold set as a reference for applying to a receiver. As described above, the reference CQI may be set through the A and B embodiments or may be set by a user of each receiver.

As shown, the transmitter transmits a stream to the receiver (S200). The transmitted stream may be transmitted through one antenna of the transmitter or may be simultaneously transmitted through multiple antennas. As such, a stream sent from a transmitter is sent to one or more receivers. The receiver receiving the stream measures channel quality for each antenna or channel through the received stream. Then, the highest quality value among the measured qualities (that is, the CQI value of the stream having the highest channel gain among the received streams) is identified, and the determined quality value is transmitted to the transmitter. When the CQI of the stream having the best channel gain is received from the receiver, the transmitter transmits the reference CQI to the receiver (S202 and S204).

The reference CQI may be set for each receiver in the transmitter or may be determined through embodiments such as A and B. In addition, the reference CQI may be adjusted according to the channel transmission state, the system state, and the priority of the receiver.

The reference CQI is applied to the remaining streams except the stream having the best channel gain corresponding to the CQI value received in step S202. That is, the receiver receiving the reference CQI compares the CQI of the remaining stream with the size of the received reference CQI. Then, the comparison result is transmitted to the transmitter. The remaining streams may be received through one antenna of the receiver or may be received through multiple antennas per stream.

For example, the comparison result compares the reference CQI value with the CQI of each remaining stream, and if the reference CQI value is smaller than the CQI of each stream, transmits an active signal to the transmitter. On the other hand, if the reference CQI value is greater than or equal to the CQI of each stream, the inactive signal is transmitted to the transmitter.

When such an active / inactive signal, that is, channel state information is received from the receiver, the transmitter forms antenna beamforming according to the received channel state information (S208). The meaning of forming the antenna beamforming includes the meaning that antennas having excellent channel quality or data rate may be used among a plurality of antennas provided in the transmitter.

When the antenna beamforming is formed in step S208, the stream is transmitted to the receiver using the antenna on which the beamforming is formed (S210).

6 is a block diagram illustrating an apparatus for transmitting a feedback of a receiver in a multi-user multiple transmit / receive antenna system according to an exemplary embodiment of the present invention.

Referring to FIG. 6, a receiver includes a channel quality measuring unit 210 measuring quality of each channel through a stream received from a transmitter, and a controller 220 comparing the measured quality value of each channel, that is, the CQI and the reference CQI. And a memory 230 for storing the reference CQI and a result value compared through the controller, a multiple receiver 240 for multiple reception of streams received from a transmitter, and decoding for decoding and demodulating the received streams. And a demodulator 250. In addition, the receiver includes a transmitter (not shown) for transmitting the comparison result to the transmitter.

In the following, the operation will be described based on one receiver, but it will be apparent that the described operation can be equally applied to all receivers that have received the reference CQI from the transmitter or to all receivers within the service area of the transmitter. In addition, as proposed by all the present invention generates feedback information, and transmits the generated feedback information to the transmitter.

Referring to FIG. 6, a transmitter provides a multi-antenna service to a receiver. As such, the transmitter and the receiver may be provided with a plurality of antennas to provide a multi-antenna service. That is, the receiver receives each stream through a plurality of antennas.

The channel quality measuring unit 210 measures the quality (ie, CQI) of the downlink channels through the stream received for each antenna. Alternatively, the channel quality measuring unit may measure the CQI through the stream having the highest channel quality among all the received streams. The channel quality measuring unit 210 transmits the CQI measured for each stream to the control unit 220. The controller 220 receiving the CQI measured for each stream compares the received stream CQI and the reference CQI value. The reference CQI is a value received from a transmitter and is a threshold for determining whether the antenna of the receiver is activated or deactivated.

As such, when the reference CQI is greater than or equal to the CQI of the stream, the controller 220 compares the size of the CQI and the reference CQI value of each stream, and sets the channel on which the stream is received to be inactive (ie, off mode). . The inactive signal according to the set result is stored in the memory. Alternatively, if the reference CQI is smaller than the CQI of the stream, the controller 220 sets the channel on which the stream is received to be active (that is, on mode). Then, the active signal according to the set result is stored in the memory.

The controller 220 may compare the active or inactive signals for each stream and store them in the memory, or when the comparison result of all the streams is completed, the controller 220 may store the active or inactive signals of all the streams in the memory.

Then, when the comparison of each stream or all streams is completed, an active or inactive signal stored in the memory is transmitted to the transmitter.

Hereinafter, a method of transmitting an active / inactive signal in a receiver according to an embodiment of the present invention is a method of transmitting active / inactive signals generated for each stream (case C) and a method of transmitting active / inactive signals of all streams together. (D case)

C. When transmitting active / inactive signals generated for each stream

Hereinafter, a method of transmitting and receiving feedback information of a receiver in a multi-user multi-transmit / receive antenna system according to an embodiment of the present invention will be described in detail with reference to FIG. 7A.

When the reference CQI is received from the transmitter, the receiver compares the received reference CQI with the CQI of each stream received from the transmitter (S300 and S302). Each stream may be received through one antenna of the receiver and may be received through a plurality of antennas provided in the receiver. In addition, the reference CQI is commonly applied to each stream.

If the received reference CQI is greater than or equal to the CQI of the stream received from the transmitter, the channel on which the stream is received is set to inactive (S304, S306). The setting to be inactive includes the meaning of no longer receiving a stream over the channel from a transmitter. As such, in order to no longer receive the stream, the receiver generates an inactive signal (ie, an off signal) according to the result set in step S306.

If the received reference CQI value is smaller than the CQI of each stream received from the transmitter in step S304, the channel on which the stream is received is set to be active (S304 and S310). If the channel is set to active in the process (S310), it generates an active signal (that is, an On signal) according to the set result.

The signal generated in the processes S308 and S312 (that is, an active or inactive signal) is transmitted to the transmitter (S314). When the process S314 is completed, the receiver checks whether the processes S304 to S314 have been performed for all streams (S316). That is, the receiver compares the reference CQI and the CQI of each stream with respect to all received streams. If the comparison of the reference CQI and the CQI of each stream is not completed in step S316, the process returns to step S304.

D. Transmitting active / inactive signals of all streams together

Hereinafter, a method of transmitting and receiving feedback information of a receiver in a multi-user multi-transmit / receive antenna system according to an embodiment of the present invention will be described in detail with reference to FIG. 7B.

Referring to FIG. 7B, the method of transmitting the active / inactive signals of all the streams of the receiver according to the present invention is the same as the processes of setting the channel for each stream in FIG. 7A as active or inactive (S300-S306 and S310).

When the received reference CQI is larger than or equal to the CQI of the stream, the received channel is set to be inactive (S402-S406). When the channel in which the stream is received is set to inactive in the process S406, the inactive signal for each stream according to the set result is stored in the memory in operation S408. In addition, the received reference CQI and the stream's CQI are compared, and if the received reference CQI has a smaller CQI of the stream, the channel in which the stream is received is set to be active (S410). When the channel in which the stream is received is set to be active in the step S410, the active signal for each stream according to the set result is stored in a memory of the same area stored in the step S408 (S412).

The receiver performs the processes (S404-S412) for all the streams and transmits active / inactive signals stored in the memory to the transmitter (S414).

In addition, although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary and will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, according to the present invention, even if the receiver receives a plurality of streams from the transmitter, only the active or inactive information of the channel for each stream is transmitted to the transmitter, thereby reducing the overall feedback amount.

In addition, the system performance can be increased by reducing the feedback amount, and the throughput of the transceiver can be increased.

Claims (25)

In the transmitter for receiving feedback information in a multiple transmit and receive antenna system, A channel state checking unit for determining a channel state of the receiver through the received information after transmitting reference channel quality information (CQI) to the receiver and receiving channel state information from the receiver; And a controller for controlling beamforming of multiple antennas using the identified channel state. The method of claim 1, wherein the reference CQI is Transmitter determined according to known and unknown statistical distribution of CQI received from multiple receivers. The method of claim 2, wherein if the statistical distribution of the CQI is known,

The reference CQI is determined through the CQI _reference , and the reference CQI indicates the reference CQI.

Is a transmitter indicating a probability of making a given CQI active. The method of claim 2, wherein when the statistical distribution of the CQI is not known,

A reference CQI to be used at a specific time is determined through the CQI _reference , and the CQI _reference indicates a reference CQI to be used at time t.

Represents the active rate that the system is aiming for, and

Represents the percentage of activity reported by real users at time t,

Is a transmitter representing a constant that determines the variation in the reference CQI over time. The method of claim 1, wherein the channel state information is And a channel state of the receiver includes information indicating an active or inactive state. In the transmitting and receiving method of a transmitter in a multiple transmit and receive antenna system, Determining a reference channel quality information (CQI) to be applied to multiple channels of a receiver; Transmitting the determined reference CQI to the receiver; And receiving status information of the channel generated using the reference CQI from the receiver. The feedback information of the transmitter of claim 6, further comprising: identifying the channel state of each antenna of the receiver when the channel state information is received, and forming an antenna beam of the transmitter using the identified channel state of each antenna. Receiving method. 7. The method of claim 6, wherein the reference CQI is A method of receiving feedback information of a transmitter determined according to whether or not the statistical distribution of CQIs received from multiple receivers is known. The method of claim 8, wherein when the statistical distribution of the CQI is known,

The reference CQI is determined through the CQI _reference , and the reference CQI indicates the reference CQI.

Is a method for receiving feedback information of a transmitter indicating a probability of determining a given CQI as active. The method of claim 8, wherein when the statistical distribution of the CQI is not known,

Is used to determine the reference CQI to be used at a specific time.

Represents the reference CQI to be used at time t, and

Represents the active rate that the system is aiming for, and

Represents the percentage of activity reported by real users at time t,

Is a method for receiving feedback information of a transmitter indicating a constant for determining a change width of a reference CQI over time. 7. The method of claim 6, wherein the channel state information is And receiving information indicating whether a channel state of the receiver is active or inactive. A receiver for transmitting feedback information in a multiple transmit / receive antenna system, A channel quality measuring unit measuring CQI (Channel Quality Information) of each stream received from the transmitter; A controller configured to compare the CQI of the stream with a reference CQI received from the transmitter and set a corresponding channel according to the comparison result; And a transmitter for transmitting the comparison result to a transmitter. The method of claim 12, wherein the control unit And if the CQI of the stream is greater than or equal to the reference CQI, setting the channel of the stream to an active state. The method of claim 12, wherein the control unit And if the CQI of the stream is less than the reference CQI, setting the channel of the stream to inactive. The method of claim 12, wherein the control unit And generating and controlling channel state information according to the comparison result. 16. The method of claim 15, wherein the channel state information is Receiver that is 1 bit. A method for transmitting feedback information of a receiver in a multiple transmit / receive antenna system, Receiving reference channel quality information (CQI) from a transmitter; Comparing the received reference CQI with the CQI of the stream received from the transmitter; And generating channel state information according to the comparison result and transmitting the generated channel state information to the transmitter. 18. The method of claim 17, further comprising setting a corresponding channel to be active or inactive according to a comparison of the received reference CQI and the CQI of the stream. 18. The method of claim 17, wherein the channel state information is And if the reference CQI is greater than or equal to the CQI of the stream, setting the channel on which the stream is received is inactive. 18. The method of claim 17, wherein the channel state information is And if the reference CQI is less than the CQI of the stream, setting the channel on which the stream is received to be active. In the multiple transmit and receive antenna system, A transmitter for transmitting a plurality of streams and reference channel quality information (CQI) to a receiver, and when channel state information is received from the receiver, forming a beam of an antenna based on the received channel state information; And a receiver configured to compare the received reference CQI and the CQI of the received stream, set an active or inactive of a corresponding channel according to a comparison result, and generate and transmit the channel state information according to the set result to the transmitter. Multiple transmit and receive antenna system for transmitting and receiving channel quality information. The method of claim 21 wherein the transmitter is

or

The reference CQI is determined through the CQI _reference , and the CQI _reference indicates a reference CQI.

Denotes the probability of making a given CQI active.

Represents the reference CQI to be used at time t, and

Represents the active rate that the system is aiming for, and

Represents the percentage of activity reported by real users at time t,

Is a multiple transmit / receive antenna system for transmitting and receiving channel quality information indicating a constant that determines a change width of a reference CQI over time. The method of claim 21 wherein the transmitter is Groups of receivers having poor CQI because they are located in the outer region or shadow area of a cell, or conversely group receivers having a good CQI, and transmit / receive channel quality information for transmitting and receiving common reference CQI to the grouped receivers. Antenna system. In the transmitting and receiving method of a multiple transmit and receive antenna system, Determining, by the transmitter, a reference CQI using channel quality information (CQI) of the stream received from the receiver, and transmitting the determined reference CQI to the receiver; When the receiver receives the reference CQI, comparing the received reference CQI with a CQI of a stream received from the transmitter; And setting the channel on which the stream is received according to the comparison result as active or inactive, and transmitting channel state information according to the setting result to the transmitter. The method of claim 24, wherein the reference CQI is Depending on the statistical distribution of CQIs received from multiple receivers

or

The CQI _reference indicates a reference CQI.

Denotes the probability of making a given CQI active.

Represents the reference CQI to be used at time t, and

Represents the active rate that the system is aiming for, and

Represents the percentage of activity reported by real users at time t,

The method of transmitting and receiving channel quality information indicating a constant for determining a change width of a reference CQI over time.

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