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EP-4102760-B1 - WIRELESS COMMUNICATION BASE STATION DEVICE, WIRELESS COMMUNICATION TERMINAL, AND CONTROL INFORMATION CREATION METHOD

EP4102760B1EP 4102760 B1EP4102760 B1EP 4102760B1EP-4102760-B1

Inventors

  • NISHIO, AKIHIKO
  • NAKAO, SEIGO
  • SAITO, YOSHIKO
  • GOLITSCHEK EDLER VON ELBWART, ALEXANDER

Dates

Publication Date
20260506
Application Date
20090810

Claims (14)

  1. A base station (100) comprising: circuitry (102) adapted to assign first control information, which includes resource assignment information indicating a first resource allocated to a terminal in a first component carrier (CC) out of multiple CCs configured for the terminal, to a first search space configured for resource assignment in the first CC, and to assign second control information, which includes resource assignment information indicating a second resource allocated to the terminal in a second CC out of the multiple CCs, to a second search space configured for resource assignment in the second CC, the first search space being different from the second search space; and a transmitter (110) adapted to transmit, to the terminal, the first control information and the second control information on one out of the multiple CCs.
  2. The base station (100) according to claim 1, wherein the first control information includes information indicating the first CC, and the second control information includes information indicating the second CC.
  3. The base station (100)according to claim 1, wherein the first CC and the second CC have frequencies different from each other.
  4. The base station (100) according to claim 1, wherein a CRC scrambled by a terminal ID is attached for each of the first control information and the second control information.
  5. The base station (100) according to claim 1, wherein the first search space is defined by a plurality of control channel elements that are specific to the first CC, and the second search space is defined by a plurality of control channel elements that are specific to the second CC.
  6. The base station (100) according to claim 1, wherein at least one of the first control information and the second control information includes the resource assignment information indicating an uplink resource allocated to the terminal, and said communication device comprises a receiver (112) adapted to receive data based on the resource assignment information.
  7. The base station (100) according to claim 1, wherein at least one of the first control information and the second control information includes the resource assignment information indicating a downlink resource allocated to the base station, and said transmitter transmits, to the terminal, data based on the resource assignment information.
  8. A communication method performed by a base station (100), the communication method comprising: assigning first control information, which includes resource assignment information indicating a first resource allocated to a terminal in a first component carrier (CC) out of multiple CCs configured for the terminal, to a first search space configured for resource assignment in the first CC; assigning second control information, which includes resource assignment information indicating a second resource allocated to the terminal in a second CC out of the multiple CCs, to a second search space configured for resource assignment in the second CC, the first search space being different from the second search space; and transmitting, to the terminal, the first control information and the second control information on one out of the multiple CCs.
  9. The communication method according to claim 8, wherein the first control information includes information indicating the first CC, and the second control information includes information indicating the second CC.
  10. The communication method according to claim 8, wherein the first CC and the second CC have frequencies different from each other.
  11. The communication method according to claim 8, wherein a CRC scrambled by a terminal ID is attached for each of the first control information and the second control information.
  12. The communication method according to claim 8, wherein the first search space is defined by a plurality of control channel elements that are specific to the first CC, and the second search space is defined by a plurality of control channel elements that are specific to the second CC.
  13. The communication method according to claim 8, wherein at least one of the first control information and the second control information includes the resource assignment information indicating an uplink resource allocated to the terminal, and said communication method comprises receiving data based on the resource assignment information.
  14. The communication method according to claim 8, wherein at least one of the first control information and the second control information includes the resource assignment information indicating a downlink resource allocated to the terminal, and said communication method comprises transmitting, to the terminal, data based on the resource assignment information.

Description

Technical Field The present invention relates to a radio communication base station apparatus and a control information generating method. Background Art 3GPP-LTE (3rd Generation Partnership Project Radio Access Network Long Term Evolution) adopts OFDMA (Orthogonal Frequency Division Multiple Access) as a downlink communication scheme, and SC-FDMA (Single Carrier Frequency Division Multiple Access) as an uplink communication scheme (for example, see Non-Patent Literatures 1, 2 and 3.) With LTE, a radio communication base station apparatus (hereinafter abbreviated as "base station") communicates with radio communication terminal apparatuses (hereinafter abbreviated as "terminals") by assigning resource blocks (RBs) in the system band to terminals, per time unit referred to as subframe. In addition, a base station transmits control information to notify, to terminals, the result of assignment of resources for downlink data and uplink data. This control information is transmitted to terminals using downlink control channels, for example, PDCCHs (physical downlink control channels.) Here, LTE supports a frequency band having the maximum width of 20 MHz as the system bandwidth. In addition, a base station transmits a plurality of PDCCHs at the same time to assign a plurality of terminals to one subframe. At this time, the base station transmits a PDCCH including CRC bits masked (scrambled) with a destination terminal ID to identify each PDCCH destination terminal. Then, a terminal performs blind-decoding on a plurality of PDCCHs which may be directed to the terminal by demasking (or descrambling) CRC bits in the plurality of PDCCHs, with its terminal ID to detect the PDCCH directed to the terminal. In addition, standardization of 3GPP LTE-Advanced that realizes faster communication than by LTE has been started. With LTE-Advanced, in order to realize a downlink transmission speed equal to or higher than the maximum 1 Gbps and an uplink transmission speed equal to or higher than the maximum 500 Mbps, base stations and terminals (hereinafter "LTE+ terminals") that are able to communicate with each other at a wideband frequency equal to or higher than 40 MHz, will be employed. In addition, an LTE-Advanced system is required to accommodate not only LTE+ terminals but also terminals (hereinafter "LTE terminals") supporting an LTE system. In addition, with LTE-Advanced, a band aggregation scheme for communication by connecting a plurality of frequency bands, is proposed. Here, a base unit of communication bands (hereinafter "component bands") is a frequency band having a width of 20 MHz. Therefore, LTE-Advanced realizes a system bandwidth of 40 MHz by connecting two component bands. In addition, with LTE-Advanced, studies are underway to associate component bands in the uplink (hereinafter "uplink component bands") with component bands in the downlink (hereinafter "downlink component bands") one by one (e.g. Non-Patent Literature 4.) That is, a base station notifies resource assignment information about each component band to terminals using the downlink component band in each component band. For example, a terminal that performs transmission in a wideband of 40 MHz (terminal using two component bands) acquires resource assignment information about two component bands by receiving PDCCHs allocated to the downlink component band in each component band. Therefore, in an LTE-Advanced system, a base station can notify resource assignment information per component band, to terminals in both cases where one component band is used (for example, in a case of communication with LTE terminals supporting a band of 20 MHz), and where a plurality of component bands are used (for example, in a case of communication with LTE+ terminals supporting a band of 40 MHz.) That is, a base station can use the same notifying method between LTE terminals and LTE+ terminals, so that it is possible to construct a simple system. Citation List Non-Patent Literature [NPL 1] 3GPP TS 36.211 V8.3.0, "Physical Channels and Modulation (Release 8)," May 2008[NPL 2] 3GPP TS 36.212 V8.3.0, "Multiplexing and channel coding (Release 8)," May 2008[NPL 3] 3GPP TS 36.213 V8.3.0, "Physical layer procedures (Release 8)," May 2008[NPL 4] 3GPP TSG RAN WG1 meeting, R1-082468, "Carrier aggregation LTE-Advanced," July 2008ERICSSON: "Carrier aggregation in LTE- Advanced", R1-082468, discloses some high-level design aspects on LTE-Advanced including mechanisms, e.g. DRX per component carrier, to allow an LTE-Advanced terminal to monitor a smaller bandwidth that the system bandwidth.MOTOROLA: "Search Space Definition: Reduced PDCCH Blind Detection for Split PDCCH Search Space", R1-080079 relates to a method of splitting a 8 CCE DL or 8CCE UL PDCCH search space to reduce the number of total PDCCH blind detections.WO 2010/013963 A2 discloses a method and an apparatus of transmitting control information in a wireless communication system. The method includes transmitting fir