EP-4344327-B1 - WIRELESS COMMUNICATION BASE STATION DEVICE, WIRELESS COMMUNICATION TERMINAL DEVICE, AND CHANNEL ALLOCATION METHOD

EP4344327B1EP 4344327 B1EP4344327 B1EP 4344327B1EP-4344327-B1

Inventors

NAKAO, SEIGO
NISHIO, AKIHIKO
IMAMURA, DAICHI

Dates

Publication Date: 20260506
Application Date: 20090807

Claims (6)

A communication apparatus (100, 800) using a carrier aggregation comprising at least two downlink component carriers and at least one uplink component carrier, the communication apparatus comprising: a receiver (102), which is adapted a) to receive, in operation, first downlink resource allocation information for a first downlink component carrier and uplink resource allocation information for an uplink component carrier on the first downlink component carrier, b) to receive, in operation, second downlink resource allocation information for a second downlink component carrier, which is different from the first downlink component carrier, c) to receive, in operation, first downlink data on the first downlink component carrier in accordance with the first downlink resource allocation information, and d) to receive, in operation, second downlink data on the second downlink component carrier in accordance with the second downlink resource allocation information; and a transmitter (118), which is adapted to transmit, in operation, uplink data on the uplink component carrier in accordance with the uplink resource allocation information, wherein the receiver is adapted to receive, in operation, an Acknowledgement/Negative-acknowledgement, ACK/NACK, signal for the uplink data in a resource of a physical hybrid-ARQ indicator channel, PHICH, only on the first downlink component carrier, on which the uplink resource allocation information is received, out of the first downlink component carrier and the second downlink component carrier, and the resource of the PHICH is determined based on a resource block indicated by the uplink resource allocation information.
The communication apparatus according to claim 1, wherein the first and second downlink resource allocation information are received in a physical downlink control channel, PDCCH, of the first and second downlink component carriers.
The communication apparatus according to claim 1, wherein the second downlink component carrier is set only for an LTE-advanced user equipment.
A communication method using a carrier aggregation comprising at least two downlink component carriers and at least one uplink component carrier, the communication method comprising: receiving first downlink resource allocation information for a first downlink component carrier and uplink resource allocation information for a uplink component carrier on the first downlink component carrier; receiving second downlink resource allocation information for a second downlink component carrier, which is different from the first downlink component carrier; receiving first downlink data on the first downlink component carrier in accordance with the first downlink resource allocation information; receiving second downlink data on the second downlink component carrier in accordance with the second downlink resource allocation information; transmitting uplink data on the uplink component carrier in accordance with the uplink resource allocation information; and receiving an Acknowledgement/Negative-acknowledgement, ACK/NACK, signal for the uplink data in a resource of a physical hybrid-ARQ indicator channel, PHICH, only on the first downlink component carrier, on which the uplink resource allocation information is received, out of the first downlink component carrier and the second downlink component carrier, and the resource of the PHICH is determined based on a resource block indicated by the uplink resource allocation information.
The communication method according to claim 4, wherein the first and second downlink resource allocation information are received in a physical downlink control channel, PDCCH, of the first and second downlink component carriers.
The communication method according to claim 4, wherein the second downlink component carrier is set only for an LTE-advanced user equipment.

Description

Technical Field The present invention relates to a communication apparatus and a communication method. Background Art In 3GPP-LTE, an OFDMA (Orthogonal Frequency Division Multiple Access) is adopted as a downlink communication scheme. In a radio communication scheme adopting 3GPP LTE, a radio communication base station apparatus (hereinafter simply "base station") transmits a synchronization channel ("SCH") and broadcast channel ("BCH") using predetermined communication resources. Then, first, a radio communication terminal apparatus (hereinafter simply "terminal") secures synchronization with the base station by capturing the SCH. After that, the terminal obtains parameters unique to the base station (such as a frequency bandwidth) by reading BCH information (see Non-Patent Literatures 1, 2 and 3). Also, in 3GPP LTE, HARQ (Hybrid Automatic Repeat reQuest) is applied to uplink data transmitted from the terminal to the base station in uplink. In HARQ, the base station performs CRC (Cyclic Redundancy Check) detection of uplink data and feeds back an ACK (Acknowledgement) if CRC=OK (no error) or a NACK if CRC=NG (error present), to a mobile station as a response signal. These response signals are transmitted via a physical channel for downlink response signal transmission such as PHICH (Physical Hybrid-ARQ Indicator Channel). Also, standardization of 3GPP LTE-advanced, which realizes faster communication than 3GPP LTE, has been started (see Non-Patent Literature 4). The 3GPP LTE-advanced system (hereinafter "LTE+ system") follows the 3GPP LTE system (hereinafter "LTE system"). Citation List GB 2 439 367 claims Uplink and downlink scheduling information transmitted on a control channel to a mobile device requires varying content depending on the current state of the device. For instance an ACK/NACK message may or may not be required, resulting in different control channel sizes. Control channel sizes are fixed by transmitting ACK/NACK messages on a separate channel that is different from the control channel. 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 TR 36.913 V8.0.0, "Requirements for Further Advancements for E-UTRA (LTE-Advanced) (Release 8)," June 2008 Summary of Disclosure Technical Problem In 3GPP LTE-advanced, to realize downlink transmission speed equal to or greater than maximum 1 Gbps, it is expected to adopt a base station and terminal that can perform communication in a wideband frequency equal to or greater than 40 MHz. Also, in 3GPP LTE-Advanced, communication bandwidths may be made asymmetric between uplink and downlink, taking into account the difference between a throughput request for uplink and a throughput request for downlink. To be more specific, in 3GPP LTE-Advanced, the downlink communication bandwidth may be made wider than the uplink communication bandwidth. Here, a base station supporting the LTE+ system (hereinafter "LTE+ base station") is designed to be able to perform communication using a plurality of "component bands." Here, a "component band" is a band having a maximum 20 MHz width, and is defined as a reference unit of a communication band. Further, a "component band" in downlink (hereinafter "downlink component band") may be defined as a band divided by downlink frequency band information in a BCH broadcasted from a base station or a band defined by bandwidth in a case where a physical downlink control channel (PDCCH) is placed in the frequency domain in a distributed manner. Also, a "component band" in uplink (hereinafter "uplink component band") may be defined as a band divided by uplink frequency band information in a BCH broadcasted from a base station or a reference unit in a communication band equal to or below 20 MHz including a PUCCH at both end parts. Also, a "component band" may be expressed as "component carrier(s)" in English in 3GPP LTE. An LTE+ base station supports an LTE+ system support terminal (hereinafter "LTE+ terminal"). LTE+ terminals include a terminal that can perform communication using only one component band (hereinafter "type-1 LTE+ terminal") and a terminal that can perform communication using a plurality of component bands (hereinafter "type-2 LTE+ terminal"). Also, the LTE+ base station needs to support not only the above LTE+ terminal but also a terminal that supports the LTE system and that can perform communication using only one component band (hereinafter "LTE terminal"). That is, the LTE+ system is designed to be able to assign a plurality of component bands to single communication, and follows the LTE system in which single communication is independently assigned to each component band. FIG.1 and FIG.2 show an example of placing channels in the LTE+ system in which communication bandwidths (i.e. the