KR101414709B1 - Apparatus and method for communicating control information in broadband wireless communication system - Google Patents

Abstract

The present invention relates to a control information communication apparatus and method in a broadband wireless communication system. A method of operating a terminal according to the present invention includes OFDM demodulating a received signal and converting the received signal into frequency domain data; extracting a map indicator from the frequency domain data; And determining whether to decode the resource allocation message by demodulating the MAP indicator into an orthogonal code, wherein the determining comprises: correlating the MAP indicator with a PN code corresponding to the corresponding CID; And determining whether to decode the resource allocation message according to the determination.

Broadband wireless access, map message, CDM

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a control information communication apparatus and method in a broadband wireless communication system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control information communication apparatus and method in a broadband wireless communication system, and more particularly, to an apparatus and method for a terminal to selectively decode broadcast control information.

Generally, a communication system has evolved mainly in voice service, and is gradually evolving into a communication system capable of not only voice but also data service and various multimedia services. The voice-oriented communication system does not satisfy the rapidly increasing user's service desire because the transmission bandwidth is relatively small and the fee for use is high. In addition, due to the development of the telecommunication industry and the increase of users' demand for the internet service, there is a growing need for a communication system capable of efficiently providing the Internet service. Accordingly, it is introduced to a broadband wireless communication system for efficiently providing Internet service.

Since the broadband wireless communication system uses an OFDM / OFDMA (Orthogonal Frequency Division Multiplexing / Orthogonal Frequency Division Multiple Access) scheme, that is, by transmitting a physical channel signal using a plurality of subcarriers, It is possible. The wireless access method of the broadband wireless communication system is standardized in the IEEE 802.16 standardization group of the Institute of Electrical and Electronics Engineers, which is one of the international standardization organizations.

In the OFDM / OFDMA-based broadband wireless communication system, in order to freely allocate the uplink / downlink in various forms, the base station transmits information describing uplink / downlink resource allocation every frame. In the IEEE 802.16 system, a MAP message plays the role.

FIG. 1 shows a frame structure of a typical IEEE 802.16 series system.

As shown, a frame is composed of one downlink frame and one uplink frame. The DL frame is a period in which the BS transmits data to the UEs, and the UL frame is a period in which data is transmitted from the UE to the BS in a predetermined area.

The DL frame is composed of a preamble, a downlink (DL) MAP, an uplink (UL) MAP, and downlink data bursts. The uplink frame is composed of a plurality of control regions and uplink data bursts. Here, the data burst may include not only data traffic but also control messages (e.g., DCD message, UCD message, PAG-ADV message, TRF-IND message, NBR-ADV message, etc.).

The DL preamble is used for initial synchronization acquisition and cell search of the UE, the MAP includes information indicating the area of downlink data bursts, and the UL MAP includes information indicating the structure of the UL frame.

The control region of the UL frame includes a ranging region, a CQICH region, and an ACKCH region. The ranging region is an area where a mobile station can upload a code without allocating a base station, and includes an initial ranging region and a periodic ranging region. The CQICH region is an area for the UE to report the downlink channel state. The ACKCH field is an area for reporting whether a downlink data burst is received or not.

Generally, the frame structure is determined by the base station, and the terminal receives the MAP message transmitted by the base station every frame, thereby confirming the frame structure and the allocation information. The MAP message is a broadcast message received by all of the UEs, and all UEs must decode the MAP message every frame regardless of data reception. That is, a terminal that does not actually transmit and receive data must decode the MAP message. As described above, when decoding a MAP message for each frame, power is consumed due to unnecessary processing (operation). It is more important to reduce the power consumption of the terminal with a portable device. In other words, you should increase battery life by eliminating unnecessary processing.

Accordingly, it is an object of the present invention to provide an apparatus and a method for selectively decoding a resource allocation message broadcasted in a broadband wireless communication system.

It is another object of the present invention to provide an apparatus and method for reducing power consumption by eliminating unnecessary processing in a broadband wireless communication system.

It is another object of the present invention to provide an apparatus and method for communicating an indicator for informing whether a resource allocation message is decoded in a broadband wireless communication system.

According to an aspect of the present invention, there is provided a base station apparatus in a broadband wireless communication system, including: a controller for performing resource scheduling; a message configurer for generating a resource allocation message according to the resource scheduling result; An indicator generator for generating a MAP indicator by adding a unique orthogonal code for each resource-allocated connection according to a scheduling result, and a transmitter for broadcasting the map indicator and the resource allocation message, The indicator generator includes a code generator for generating a PN code for each of the connections to which resources are allocated from the controller and an adder for adding the PN codes from the code generator in a CDM (Code Division Multiplexing) .

According to another aspect of the present invention, there is provided a receiving apparatus in a broadband wireless communication system, comprising: a receiver for performing OFDM demodulation of a received signal and converting the received signal into frequency domain data; resource demapping for extracting a map indicator from frequency- And a determiner for determining whether to decode the resource allocation message by demodulating the MAP indicator into an orthogonal code corresponding to its connection and determining whether to decode the resource allocation message, wherein the determiner comprises: a code for correlating the map indicator with a PN code corresponding to a corresponding CID; And a determiner for determining whether a correlation value is peaked from the code demodulator and determining whether to decode the resource allocation message according to the determination.

According to another aspect of the present invention, there is provided a method of operating a base station in a broadband wireless communication system, the method comprising: performing resource scheduling; configuring a resource allocation message according to the resource scheduling result; Generating a MAP indicator by adding a unique orthogonal code for each resource-allocated connection; and transmitting the MAP indicator and the resource allocation message, Generating a PN code for each resource-allocated connection; and generating the map indicator by adding the generated PN codes according to a Code Division Multiplexing (CDM) scheme.

According to another aspect of the present invention, there is provided a method of operating a terminal in a broadband wireless communication system, the method comprising: OFDM-demodulating a received signal into frequency domain data; And determining whether to decode the resource allocation message by demodulating the MAP indicator into an orthogonal code corresponding to a connection of the UE, wherein the determining comprises: correlating the MAP indicator with a PN code corresponding to the corresponding CID Determining whether the correlation value is peaked, and determining whether to decode the resource allocation message according to the determination.

As described above, since the present invention can selectively decode a message broadcasted by a mobile station in a wireless communication system, there is an advantage that power consumption due to an unnecessary decoding operation can be reduced.

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

Hereinafter, a method for a terminal to selectively decode a message broadcast in a broadband wireless communication system will be described.

Hereinafter, a system based on OFDM / OFDMA will be described as an example, but the present invention can be easily applied to any wireless communication system.

2 shows a frame structure according to an embodiment of the present invention.

As shown in the figure, a frame structure according to the present invention is basically similar to the structure of FIG. 1, and a CDM (Code Division Multiplexing) section is located in a preamble and a MAP message. The present invention assigns unique orthogonal codes (e.g., PN codes, Walsh codes, etc.) to each of a CID (Connection IDentifier) or a control message (e.g., a paging message). Adds the orthogonal codes for the CIDs to which the resources are allocated in the current frame by the CDM method, generates a MAP indicator, and transmits the MAP indicator through the CDM interval.

The control message of a small size may be multiplied by the unique orthogonal code, and may be added together with the MAP indicator in the CDM scheme. The terminal demodulates the MAP indicator received in the CDM section into an orthogonal code corresponding to its own CID and decides whether to decode the MAP message according to the demodulation result (resource allocation). In addition, the UE can acquire control information by demodulating a signal received in a CDM interval with an orthogonal code of a corresponding control message. Hereinafter, a case where a MAP indicator is transmitted through a CDM section will be described as an example.

FIG. 3 shows a configuration of a transmitter in a broadband wireless communication system according to an embodiment of the present invention.

3 shows a transmitter of a base station and includes a controller 300, a MAP message configurer 302, a burst configurator 304, a code / modulator 306, a resource mapper 308, an OFDM modulator 310, A radio frequency (RF) processor 312, a PN code generator 314, and a code adder 316.

3, the controller 300 performs resource scheduling for the current frame using channel information (e.g., CQI (Channel Quality Information), service type (QoS), or the like) for each terminal And provides the scheduling result (resource allocation information, etc.) to the MAP message composer 302. In addition, the controller 300 provides CIDs allocated resources to the PN code generator 314 in this frame.

The PN code generator 314 generates unique PN codes for each of the CIDs from the controller 300 sequentially or in parallel. For example, the PN code generator 314 may include a mapping table (memory table) between CID and PN codes. The PN code generator 314 reads a PN code for each of the CIDs from the controller 300, can do. The PN code generator 314 may include a PN code generator as shown in FIG. 7, and may set a seed value different for each CID, thereby generating PNs for each of the CIDs from the controller 300. For example, Code. The code adder 316 adds the at least one PN code generated from the PN code generator 314 by the CDM method and provides the MAP indicator to the resource mapper 308.

Meanwhile, the burst configurer 304 configures the transmission data from the upper layer as a burst under the control of the controller 300.

The code / modulator 306 codes and modulates the MAP message from the MAP message composer 302 according to a predetermined Modulation and Coding Scheme (MCS) level. Next, the code / modulator 305 codes and modulates the bursts from the burst configurer 304 according to a predetermined MCS level.

The resource mapper 308 maps the preamble signal to the front end of the frame (first OFDM symbol), and then maps the MAP signal from the code adder 306 to a resource mapping (subcarrier mapping). Then, the resource mapper 308 maps bursts (MAP bursts, data bursts) from the code / modulator 306 to predetermined resources and outputs them.

The OFDM modulator 310 performs IFFT (Inverse Fast Fourier Transform) operation on the resource mapped data from the resource mapper 308 to generate sample data and inserts a guard interval (e.g., a cyclic prefix) into the sample data OFDM symbol. The RF processor 312 converts the sample data from the OFDM modulator 310 into an analog signal, converts the analog signal into an RF signal, and transmits the RF signal through an antenna.

FIG. 4 shows a configuration of a receiver in a broadband wireless communication system according to an embodiment of the present invention.

4 shows a receiver of a UE and includes an RF processor 400, an OFDM demodulator 402, a resource demapper 404, a demodulator / decoder 406, a MAP message decoder 408, a service data unit (SDU) ) Assembler 410, a controller 412, a code demodulator 414, and a determiner 416.

Referring to FIG. 4, the RF processor 400 converts an RF signal received through an antenna into a baseband signal, and converts the baseband signal into digital sample data. The OFDM demodulator 402 removes a guard interval from the sample data from the RF processor 400 and performs Fast Fourier Transform (FFT) on the sample data from which the guard interval is removed to output frequency-domain data.

The resource demapper 404 extracts preamble data from the frequency domain data from the OFDM demodulator 402 and provides it to a channel estimator (not shown). Next, the resource demapper 404 extracts a MAP indicator and provides it to a code demodulator 414 do. Next, the resource demapper 404 extracts bursts (MAP bursts and data bursts) from the frequency domain data and provides the extracted bursts (MAP bursts and data bursts) to the demodulator / decoder 406.

The code demodulator 414 demodulates (or correlates) the MAP indicator from the resource demapper 404 with an orthogonal code corresponding to its own CID and outputs the orthogonal code. Here, when a plurality of connections are set, the code demodulator 414 demodulates the MAP indicator into orthogonal codes corresponding to a plurality of CIDs. The determiner 416 determines whether to decode the MAP message according to the code demodulation value from the code demodulator 414, and provides the result to the controller 412. At this time, if decoding of the MAP message is determined, the controller 412 instructs the demodulator / decoder 406 to decode the MAP message.

The demodulator / decoder 406 demodulates and decodes the MAP message received from the resource demapper 404 according to the determined MCS level under the control of the controller 412. The MAP message decoder 408 decodes the MAP message from the demodulator / protector 406 and provides resource allocation information (MAP_IE) corresponding to the CID to the controller 412. The controller 412 then controls the resource demapper 404 and the demodulator / protector 406 according to resource allocation information (data burst location, MCS level, etc.) from the MAP message decoder 408.

The resource demapper 404 extracts a data burst of a corresponding region from data in the frequency domain under the control of the controller 412 and outputs the data burst. The demodulator / decoder 406 demodulates and decodes the data burst from the resource demapper 404 to the corresponding MCS level under the control of the controller 412, and transfers it to the SDU assembler 410. The SDU assembler 410 assembles the data from the demodulator / decoder 406 into a service data unit and transfers it to an upper layer processing unit (not shown).

5 illustrates an operation procedure of a transmitter in a broadband wireless communication system according to an embodiment of the present invention.

Referring to FIG. 5, in step 501, the transmitter (base station) performs resource scheduling for data to be transmitted and received for each frame. In step 503, the transmitter generates a MAP message according to the resource scheduling result. The MAP message includes resource allocation information (MAP_IEs) for CIDs (connection identifiers) to which resources are allocated at this time. In other words, the MAP message includes resource allocation information on data bursts transmitted and received in the current frame.

In step 505, the transmitter identifies CIDs to which resources are allocated at this time. In step 505, the transmitter generates a unique PN code for each of the identified CIDs, and generates a MAP indicator by adding the generated PN codes in a CDM scheme.

Then, the transmitter checks the current time in step 509 to check if the frame starts. When the frame starts, the transmitter proceeds to step 511 and transmits a preamble signal in the first section of the frame. After transmitting the preamble signal, the transmitter transmits the MAP indicator in step 513. Next, the transmitter transmits the MAP message to the MAP indicator in step 515, and maps the data bursts to predetermined resources according to a scheduling result in step 517, and transmits the MAP burst to the transmitter. On the other hand, in the case of a TDD (Time Division Duplexing) system, the transmitter receives data from the UEs during an uplink interval of the frame according to the scheduling result.

FIG. 6 illustrates an operation procedure of a receiver in a broadband wireless communication system according to an embodiment of the present invention.

Referring to FIG. 6, the receiver (terminal) checks in step 601 whether a frame is received. If the reception of the frame is detected, the receiver proceeds to step 603 and receives a preamble signal in the first section of the frame. The received preamble signal is used for synchronization acquisition and channel estimation.

In step 605, the receiver receives the MAP indicator in succession to the preamble signal. In step 607, the receiver demodulates the MAP indicator into an orthogonal code (PN code) corresponding to its own CID. In step 609, the receiver checks the demodulation value and detects whether an orthogonal code of the corresponding CID is received. That is, in step 609, the receiver determines whether to decode the MAP message according to the code demodulation value.

If the MAP indicator does not include the orthogonal code of the corresponding CID, that is, the decoding of the MAP message is not required, the receiver discards the received MAP burst and waits until the next frame is received. If the MAP indicator includes the orthogonal code of the corresponding CID, that is, decoding of the MAP message is required, the receiver proceeds to step 611 to decode the MAP message received following the MAP indicator, And acquires resource allocation information (burst position, MCS level, etc.) corresponding to the corresponding CID from the decoding result. In step 613, the receiver receives the data burst using the resource allocation information. Meanwhile, in the case of a TDD (Time Division Duplexing) system, the receiver transmits a data burst to the Node B during an uplink interval of the frame according to the resource allocation information.

Although the embodiment of the present invention has been described above with reference to the MAP indicator, as described above, the control message can also be transmitted by the CDM method. For example, when the paging message is transmitted by the CDM scheme as in the present invention, the MAP decoding process can be eliminated, thereby reducing power consumption of the MS operating in the idle mode. In addition, since the control message can be decoded prior to the data burst, the delay for the control information can be reduced.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

1 is a diagram showing a frame structure of a typical IEEE 802.16 series system;

2 is a diagram showing a frame structure according to an embodiment of the present invention;

3 is a diagram illustrating a configuration of a transmitter in a broadband wireless communication system according to an embodiment of the present invention.

4 is a diagram illustrating a configuration of a receiver in a broadband wireless communication system according to an embodiment of the present invention.

5 is a diagram illustrating an operation procedure of a transmitter in a broadband wireless communication system according to an embodiment of the present invention.

6 is a diagram illustrating an operation procedure of a receiver in a broadband wireless communication system according to an embodiment of the present invention.

7 is a diagram showing a configuration of a PN code generator according to an embodiment of the present invention;

Claims (20)

A base station apparatus in a broadband wireless communication system, A controller for performing resource scheduling; A message composer for generating a resource allocation message according to the resource scheduling result, An indicator generator for generating a MAP indicator by adding a unique orthogonal code for each resource-allocated connection according to the resource scheduling result; And a transmitter for broadcasting the map indicator and the resource allocation message, Wherein the indicator generator comprises: A code generator for generating a PN code for each of the connections to which resources are allocated from the controller, And an adder for adding the PN codes from the code generator by a CDM (Code Division Multiplexing) method. delete The method according to claim 1, Wherein the code generator comprises a mapping memory table between a CID (connection identifier) and a PN code, and reads a PN code for each connection from the controller from the memory table. The method according to claim 1, Wherein the code generator comprises a PN code generator and generates a PN code by setting different seed values for each CID. 2. The apparatus of claim 1, A modulator for coding and modulating a resource allocation message and a transmission data burst from the message composer according to a predetermined MCS level; A resource mapper mapping the map indicator from the indicator generator to a predetermined resource and outputting the map indicator, mapping the burst from the modulator to a predetermined resource, An OFDM modulator for IFFT-calculating data from the resource mapper to generate an OFDM symbol; And an RF processor for converting an OFDM symbol from the OFDM modulator into an RF signal and transmitting the RF signal. A receiving apparatus in a broadband wireless communication system, A receiver for performing OFDM demodulation on a received signal and converting the OFDM demodulated signal into frequency domain data; A resource demapper for extracting a map indicator from the frequency domain data from the receiver, And a determiner for determining whether to decode the resource allocation message by demodulating the map indicator into an orthogonal code corresponding to its connection, The determiner, A code demodulator for correlating the map indicator with a PN code corresponding to the corresponding CID, And a determiner for determining whether a correlation value is peaked from the code demodulator and determining whether to decode the resource allocation message according to the determination. delete The method according to claim 6, Wherein the map indicator is received between a preamble and a resource allocation message. The method according to claim 6, A decoder for demodulating and decoding the received MAP burst at a predetermined MCS level when decoding of the resource allocation message is required; A message analyzer for decoding the MAP message from the decoder and acquiring resource allocation information corresponding to the CID, And a controller for controlling the decoding of the data burst of the corresponding area according to the obtained resource allocation information. The method according to claim 6, Further comprising a controller for controlling to wait until the next frame is received after discarding the received MAP burst if decoding of the resource allocation message is not required. A method of operating a base station in a broadband wireless communication system, Performing resource scheduling; Configuring a resource allocation message according to the resource scheduling result; Generating a MAP indicator by adding a unique orthogonal code for each resource-allocated connection according to the resource scheduling result; And transmitting the map indicator and the resource allocation message, The map indicator generation process includes: Generating a PN code for each resource-allocated connection; And generating the map indicator by adding the generated PN codes using a CDM (Code Division Multiplexing) scheme. delete 12. The method of claim 11, Wherein the PN code generation process generates a PN code using a mapping memory table between a CID (connection identifier) and a PN code. 12. The method of claim 11, Wherein the PN code generation step generates a PN code by setting a seed value different for each CID to a PN code generator. 12. The method of claim 11, Coding and modulating the resource allocation message and the transmission data burst according to a predetermined MCS level; Mapping the map indicator to a predetermined resource, and mapping the modulated burst to a predetermined resource; Generating an OFDM symbol by performing IFFT on the resource-mapped data; And converting the OFDM symbol into an RF signal and transmitting the RF signal. A method of operating a terminal in a broadband wireless communication system, Performing OFDM demodulation on a received signal to convert the OFDM demodulated data into frequency domain data, Extracting a map indicator from the frequency domain data; Demodulating the MAP indicator into an orthogonal code corresponding to a connection of the UE, and determining whether to decode the resource allocation message, In the determination process, Correlating the map indicator with a PN code corresponding to the corresponding CID; Determining whether the correlation value is a peak, and determining whether to decode the resource allocation message according to the determination. delete 17. The method of claim 16, Wherein the map indicator is received between a preamble and a resource allocation message. 17. The method of claim 16, Demodulating and decoding the received MAP burst to a predetermined MCS level when decoding of the resource allocation message is required; Decoding the decoded MAP message to obtain resource allocation information corresponding to the corresponding CID; And decoding the data burst of the corresponding region according to the obtained resource allocation information. 17. The method of claim 16, Further comprising the step of discarding the received MAP burst and waiting until the next frame is received if decoding of the resource allocation message is not required.

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