Method and apparatus for transmitting and receiving common channel information in wireless communication system

Abstract

Methods and apparatus are provided for transmission and reception of common channel information in a mobile communication system using multi-antenna-based beamforming. A number of beams to be used for transmission to a terminal is determined at a base station. The common channel information is generated corresponding to the number of beams. The common channel information is transmitted from the base station to the terminal through one of the beams.

Description

foursteeping sweeping technique proposed in embodiments of the present invention, the SCH is transmitted at every subframe in the LTE system as shown in FIG. 5. BCH is mapped to the four OFDM symbols right after the SCH in the subframe carrying the first one of the two paired SCHs as denoted by reference number 513 of FIG. 5. Similar to SCH, if the beam sweeping is applied to BCH, the BCH is transmitted over the subframes 501 to 505.

The BCH is received at the BCH positions determined based on the frame timing acquired through SCH. The BCH carries the MIB as the cell-specific information and includes SIB scheduling information for use in SIB as more detailed system information. For the beam sweeping with the FD-MIMO, an embodiment of the present invention introduces beam-specific information (hereinafter, referred to as BIB). The UE receives the MIB through BCH transmitted by the eNB, and the MIB includes the scheduling information on BIB. The UE receives a different MIB depending on the beam transmitted by the eNB, so as to receive the distinct BIB according to the received beam. If the UE receives the BCH through a certain beam, it acquires the system information corresponding to the received beam. Specifically, since the different information is received depending on the beam, the BCH is configured in the way of receiving different BIBs through different beams. The cell-specific information is transmitted in the same MIB through all the beams carrying BCHs.

Referring to FIG. 5, the BCH transmitted at the subframe 501 includes the MIB corresponding to beam 1, and the MIB includes the SIB as the cell-specific information and the scheduling information for use in the BIB corresponding to beam 1 among the five beams. The BCH transmitted at the subframe 502 includes the MIB corresponding to beam 2 and, the MB includes the SIB as the cell-specific information and scheduling information for use in receiving BIB corresponding to beam 2 among the five beams. The BCH transmitted at the subframe 503 includes the MIB corresponding to beam 3 and, the MIB includes the SIB as the cell-specific information and scheduling information for use in receiving BIB corresponding to beam 3 among the five beams. The BCH transmitted at the subframe 504 includes the MIB corresponding to beam 4 and, the MIB includes the SIB as the cell-specific information and scheduling information for use in receiving BIB corresponding to beam 4 among the five beams. The BCH transmitted at the subframe 505 includes the MIB corresponding to beam 5 and, the MIB includes the SIB as the cell-specific information and scheduling information for use in receiving BIB corresponding to beam 5 among the five beams. The BIB may include other information necessary for transmitting and receiving the signals using the beam pattern, for example, uplink random access parameter information, power control information, and TDD downlink/uplink configuration information. Particularly, the uplink random access information includes the information on the resource for transmitting Uplink Random Access Channel (UL RACH) and, if different UL RACH resources are used for respective beams, the eNB is capable of checking when the UE transmits the UL RACH so as to improve the reception beamforming gain and, if the same beam is used in transmitting the response in replay to the UL-RACH, transmission beamforming gain. If the type of the beam to receive changes due to the change of the UE location within the cell, the BIB also has to change in corresponding to the new beam. At this time, the BIB may be transmitted to the UE through the BCH corresponding to the new beam or DL-SCH.

In another embodiment of the present invention, BCH is interpreted according to beam sweeping. This embodiment is directed to an uplink random access method according to the UE location. In the first described embodiment using the beam sweeping, the beam-specific SCH is transmitted in the way of transmitting SCH per subframe, such that the UE acquires the frame timing. In the case of an LTE system, SCH is transmitted at every subframe, and the BCH is mapped to four OFDM symbols following the SCH at the subframes carrying the first of the two paired SCHs as denoted by reference number 513 of FIG. 5. Like SCH, if the beam sweeping is used, the BCH is transmitted at the subframes 501 to 505. In an embodiment of the present invention, BCH includes the information on a relationship between SCH and beam and UE operation dependent on the beam. Specifically, the UE that has received SCH is capable of acquiring the information on the currently received beam through BCH. The UEs that receive SCH at different sub-frames receive different beams, resulting in acquisition of different information. The UE receives different BCH information, i.e., different MIB information indicating the location of the BIB, interpreted according to the received beam as well as the beam information. The information-beam specific information may include the other information necessary for transmitting and receiving signal using the beam pattern such as UL random access parameter information, power control information, and TDD DL/UL configuration information.

FIGS. 8A and 8B illustrate operations of the UE when the BCH interpretation method changes according to the beam in the beam sweeping-based method, according to an embodiment of the present disclosure. FIG. 8A is a block diagram illustrating the configuration of the UE, according to an embodiment of the present invention. FIG. 8B is a flowchart illustrating the operation procedure of the UE, according to an embodiment of the present invention.

The UE receives SCH by means of a receiver 801 and an SCH detector 802, in step S801. The UE reads BCH by means of a BCH decoder 803, in step S802.

The receiver inputs the SCH information and BCH information, i.e., MIB information, to a controller 804, in step S803. The controller 804 acquires scheduling information from BIB transmitted in the two pieces of information, in step S804, and controls the receiver 801 based on the scheduling information to receive DL-SCH at the BIB transmission position and acquire the BIB information at a BIB receiver 805, in step S805.

The BIB information is input to a transmission controller 806, and the transmission controller 806 acquires the UL random access information, particularly UL-RACH resource information, included in the BIB, in step S806. Then the transmission controller controls a transmitter 807 based on the UL random access information, such that the UE performs UL random access on the resource indicated by UL-RACH resource information included in the BIB, in step S807.

FIGS. 9A and 9B are diagrams illustrating operations of the eNB for transmitting per-beam BCH and BIB in the case of applying the beam sweeping, according to an embodiment of the present invention. FIG. 9A is a block diagram illustrating a configuration of the eNB according to an embodiment of the present invention, and FIG. 9B is a flowchart illustrating the operation procedure of the eNB according to an embodiment of the present invention.

A controller 901 controls an MIB generator 902 to include the scheduling information on the beam-specific BIB in the MIB, in step S901.

The controller 901 controls a BIB generator 903 to generate the beam-specific BIB, in step S902, and controls a transmitter 904 to transmit the beam-specific MIB and BIB information using the corresponding BCH and DL-SCH, in step S903. The controller 901 controls a receiver 905 to receive UL-RACH transmitted by the UE receiving a predetermined beam.

The signal transmission/reception method of embodiments of the present invention is capable of efficiently performing the initial access at a low transmit power level in the FD-MIMO system having a few dozen or more transmit antennas.

Although the internal structures of the UE and the eNB of embodiments of the present invention have been described with reference to the accompanying drawings, each of the UE and the eNB may be configured with a transceiver for transmitting/receiving signal to/from the peer node and a controller for controlling its functions. The controller's functions of each node have been described in detailed at the respective parts.

While the invention has been shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method by a base station of a mobile communication system using multi-antenna-based, beamforming, the method comprising:

identifying a plurality of beams to be used for transmission; and

transmitting, to each terminal in a cell of the base station, common channel information through each of the plurality of the beams,

wherein the common channel information is information to be commonly applied to terminals which belong to the cell of the base station,

wherein the common channel information comprises a synchronization channel including a first synchronization signal and a second synchronization signal, and

wherein the common channel information transmitted through each of the plurality of beams to each terminal is included in different subframes in a frame and the first synchronization signal includes a beam-specific code, which is a synchronization channel-specific code determined differently depending on the beam, such that each terminal identifies a subframe carrying the first synchronization signal based on the beam-specific code for acquiring frame timing.

2. The method of claim 1, wherein the common channel information further comprises a broadcast channel.

3. The method of claim 2, wherein the broadcast channel comprises a master information block as cell-specific information, the master information block comprising scheduling information on beam-specific information including system information on a certain beam, the beam-specific information comprising at least one of uplink random access information, power control information, time Division Duplex (TDD) downlink/uplink configuration information.

4. A method by a terminal in a mobile communication system using multi-antenna-based beamforming, the method comprising:

receiving common channel information transmitted through a beam by a base station, wherein the common channel information is included in a certain subframe in a frame and comprises a synchronization channel including a first synchronization signal and a second synchronization signal, the first synchronization signal including a beam-specific code, which is a synchronization channel-specific code determined differently depending on the beam,

identifying the subframe carrying the first synchronization signal based on the beam-specific code;

acquiring frame timing based on a result of the identification of the subframe; and

receiving a signal transmitted by the base station based on the frame timing,

wherein the common channel information is transmitted through each of a plurality of beams, and the common channel information transmitted through each of the plurality of beams is included in different subframes in a frame,

wherein the common channel information is information to be commonly applied to terminals which belong to a cell of the base station.

5. The method of claim 4, wherein the common channel information further comprises a broadcast channel.

6. The method of claim 5, wherein the broadcast channel comprises a master information block as cell-specific information, the master information block comprising scheduling information on beam-specific information including system information on a certain beam, the beam-specific information comprising at least one of uplink random access information, power control information, time Division Duplex (TDD) downlink/uplink configuration information.

7. A base station in a mobile communication system using multi-antenna-based beamforming, the base station comprising:

a transceiver configured to transmit and receive signals; and

a controller configured to identify a plurality of beams to be used for transmission, and control the transceiver to transmit, to each terminal in a cell of the base station, common channel information through each of the plurality of the beams,

wherein the common channel information is information to be commonly applied to terminals which belong to the cell of the base station,

wherein the common channel information comprises a synchronization channel including a first synchronization signal and a second synchronization signal, and

wherein the common channel information transmitted through each of the plurality of beams to each terminal is included in different subframes in a frame and the first synchronization signal includes a beam-specific code, which is a synchronization channel-specific code determined differently depending on the beam, such that each terminal identifies a subframe carrying the first synchronization signal based on the beam-specific code for acquiring frame timing.

8. The base station of claim 7, wherein the common channel information further comprises a broadcast channel.

9. The base station of claim 8, wherein the broadcast channel comprises a master information block as cell-specific information, the master information block comprising scheduling information on beam-specific information including system information on a certain beam, the beam-specific information comprising at least one of uplink random access information, power control information, time Division Duplex (TDD) downlink/uplink configuration information.

10. A terminal in a mobile communication system using multi-antenna-based beamforming, the terminal comprising:

a transceiver configured to transmit and receive signals to and from a base station; and

a controller configured to control the transceiver to:

receive common channel information transmitted through a beam by a base station, wherein the common channel information is included in a certain subframe in a frame and comprises a synchronization channel including a first synchronization signal and a second synchronization signal, the first synchronization signal including a beam-specific code, which is a synchronization channel-specific code determined differently depending on the beam,

identify the subframe carrying the first synchronization signal based on the beam-specific code,

acquire frame timing based on a result of the identification of the subframe, and

receive a signal transmitted by the base station based on the frame timing,

wherein the common channel information is transmitted through each of a plurality of beams and the common channel information transmitted through each of the plurality of beams is included in different subframes in a frame,

wherein the common channel information is information to be commonly applied to terminals which belong to a cell of the base station.

11. The terminal of claim 10, wherein the common channel information further comprises a broadcast channel.

12. The terminal of claim 11, wherein the broadcast channel comprises a master information block as cell-specific information, the master information block comprising scheduling information on beam-specific information including system information on a certain beam, the beam-specific information comprising at least one of uplink random access information, power control information, time Division Duplex (TDD) downlink/uplink configuration information.

13. A terminal for processing synchronization signals and system information in a mobile communication system, the terminal comprising:

a transceiver; and

a processor configured to:

receive, from a base station via the transceiver, a block including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (BCH), wherein the block is one among a subset of blocks and each block in the subset of blocks is a candidate for receiving the PSS, SSS, and the BCH,

obtain master information in the BCH of the block, and

receive, from the base station via the transceiver, system information in a downlink shared channel based on the master information in the BCH of the block,

wherein the subset of blocks is selected from a set of blocks, and the subset of blocks is smaller than or equal to the set of blocks,

wherein the set of blocks are defined based on a time duration corresponding to 5 sub-frames of 10 sub-frames within one frame,

wherein the PSS of the block is separated from the SSS and the BCH in a time domain,

wherein the block is associated with a beam-specific code and a beam of at least one beam for the set of blocks,

wherein the set of blocks are indexed in an ascending order in the time domain,

wherein a time synchronization is identified based on the block associated with the beam-specific code, and

wherein the system information includes cell-specific information.

14. The terminal of claim 13, wherein each block among the set of blocks is numbered and a position of the block is predetermined.

15. The terminal of claim 13, wherein the processor is further configured to identify a cell identifier (ID) based on the block.

16. The terminal of claim 13, wherein the system information includes time duplex division (TDD) uplink-downlink configuration information and power related information.

17. A base station for processing synchronization signals and system information in a mobile communication system, the base station comprising:

a transceiver; and

a processor configured to:

transmit, to a terminal via the transceiver, a block including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (BCH), wherein the block is one among a subset of blocks and each block in the subset of blocks is a candidate for transmitting the PSS, SSS, and the BCH, and

transmit, to the terminal via the transceiver, system information in a downlink shared channel based on master information in the BCH,

wherein the subset of blocks is selected from a set of blocks, and the subset of blocks is smaller than or equal to the set of blocks,

wherein the set of blocks are defined based on a time duration corresponding to 5 sub-frames of 10 sub-frames within one frame,

wherein the PSS of the block is separated from the SSS and the BCH in a time domain,

wherein the master information is transmitted in the BCH,

wherein the block is associated with a beam-specific code and a beam of at least one beam for the set of blocks,

wherein the set of blocks are indexed in an ascending order in the time domain,

wherein a time synchronization is identified based on the block associated with the beam-specific code, and

wherein the system information includes cell-specific information.

18. The base station of claim 17, wherein each block among the set of blocks is numbered and a position of the block is predetermined.

19. The base station of claim 17, wherein a cell identifier (ID) is identified based on the block.

20. The base station of claim 17, the system information includes time duplex division (TDD) uplink-downlink configuration information and power related information.

21. A method for processing synchronization signals and system information in a mobile communication system, the method comprising:

receiving, from a base station, a block including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (BCH), wherein the block is one among a subset of blocks and each block in the subset of blocks is a candidate for receiving the PSS, SSS, and the BCH;

obtaining master information in the BCH of the block; and

receiving, from the base station, system information in a downlink shared channel based on the master information in the BCH of the block,

wherein the subset of blocks is selected from a set of blocks, and the subset of blocks is smaller than or equal to the set of blocks,

wherein the set of blocks are defined based on a time duration corresponding to 5 sub-frames of 10 sub-frames within one frame,

wherein the PSS of the block is separated from the SSS and the BCH in a time domain,

wherein the block is associated with a beam-specific code and a beam of at least one beam for the set of blocks,

wherein the set of blocks are indexed in an ascending order in the time domain,

wherein a time synchronization is identified based on the block associated with the beam-specific code, and

wherein the system information includes cell-specific information.

22. The method of claim 21, wherein each block among the set of blocks is numbered and a position of the block is predetermined.

23. The method of claim 21, further comprising identifying a cell identifier (ID) based on the block.

24. The method of claim 21, wherein the system information includes time duplex division (TDD) uplink-downlink configuration information and power related information.

25. A method for processing synchronization signals and system information in a mobile communication system, the method comprising:

transmitting, to a terminal, a block including a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (BCH), wherein the block is one among a subset of blocks and each block in the subset of blocks is a candidate for transmitting the PSS, SSS, and the BCH; and

transmitting, to the terminal, system information in a downlink shared channel based on master information in the BCH,

wherein the subset of blocks is selected from a set of blocks, and the subset of blocks is smaller than or equal to the set of blocks,

wherein the set of blocks are defined based on a time duration corresponding to 5 sub-frames of 10 sub-frames within one frame,

wherein the PSS of the block is separated from the SSS and the BCH in a time domain,

wherein the master information is transmitted in the BCH,

wherein the block is associated with a beam-specific code and a beam of at least one beam for the set of blocks,

wherein the set of blocks are indexed in an ascending order in the time domain,

wherein a time synchronization is identified based on the block associated with the beam-specific code, and

wherein the system information includes cell-specific information.

26. The method of claim 25, wherein each block among the set of blocks is numbered and a position of the block is predetermined.

27. The method of claim 25, wherein a cell identifier (ID) is identified based on the block.

28. The method of claim 25, wherein the system information includes time duplex division (TDD) uplink-downlink configuration information and power related information.