# US 9,439,180 B2 · Method and apparatus for channel estimation for radio link between a base station and a relay station > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,439,180 B2 - Document ID: US9439180B2 - Status: Granted - Kind: B2 - Application number: 14/246,883 - Filed: 2014-04-07 - Published: 2014-08-07 - Granted: 2016-09-06 - Earliest claimed: 2010-04-22 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Han Byul Seo; Hak Seong Kim; Ki Jun Kim; Byoung Hoon Kim; Dae Won Lee - Web page: https://patentgrep.com/patent/US9439180B2 ## CPC - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04B 7/155: Ground-based stations (H04B7/204 takes precedence) - H04L 5/0023: {Time-frequency-space} - H04L 5/0032: {Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation} - H04L 5/0044: {Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 5/0051: {of dedicated pilots, i.e. pilots destined for a single user or terminal} - H04L 5/0082: {at predetermined intervals} - H04L 5/0094: {Indication of how sub-channels of the path are allocated} - H04L 5/0039: {Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04L 5/0069: {Allocation based on distance or geographical location} - H04W 72/04: Wireless resource allocation - H04W 84/047: {using dedicated repeater stations} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A method for receiving a downlink signal at a downlink reception entity in a wireless communication system, the method includes: receiving downlink control information by demodulating an advanced Physical Downlink Control Channel (PDCCH) of a first resource block (RB) pair of a RB bundle based on a downlink channel estimated by a first Demodulation Reference Signal (DMRS) in the first RB pair; and receiving downlink data by demodulating a Physical Downlink Shared Channel (PDSCH) of a second RB pair of the RB bundle based on a downlink channel estimated by a second DMRS in the second RB pair, wherein the same DMRS pattern is used for the first and the second DMRSs, and wherein antenna ports for the first and the second DMRSs are different. ## Claims ### Claim 1 A method for receiving a downlink signal at a downlink reception entity in a wireless communication system, the method comprising: receiving downlink control inform'ation by demodulating a Physical Downlink Control Channel (PDCCH) in a first resource block (RB) pair within an RB bundle based on a downlink channel estimated by using a first Demodulation Reference Signal (DMRS) in the first RB pair; and receiving downlink data by demodulating a Physical Downlink Shared Channel (PDSCH) in one or more second RB pairs within the RB bundle based on a downlink channel estimated by using a second DMRS in the one or more second RB pairs, wherein the downlink channel estimated by using the second DMRS is estimated based on an assumption that a same precoder is applied to the one or more second RB pairs. ### Claim 2 (depends on 1) The method of claim 1, wherein the PDSCH is mapped to resource elements which are not part of the first RB pair carrying the PDCCH. ### Claim 3 (depends on 1) The method of claim 1, wherein the downlink control information includes downlink scheduling information associated with the PDSCH. ### Claim 4 (depends on 1) The method of claim 1, wherein the PDCCH is transmitted after N orthogonal frequency division multiplexing (OFDM) symbols in a downlink subframe, where N =1, 2 or 3. ### Claim 5 (depends on 1) The method of claim 1, wherein the RB bundle includes consecutive RB pairs. ### Claim 6 A method for performing downlink transmission at a downlink transmission entity in a wireless communication system, the method comprising: transmitting, in a first resource block (RB) pair within an RB bundle, downlink control information through a Physical Downlink Control Channel (PDCCH) and a first Demodulation Reference Signal (DMRS) used for estimating a downlink channel to demodulate the PDCCH; and transmitting, in one or more second RB pairs within the RB bundle, downlink data through a Physical Downlink Shared Channel (PDSCH) and a second DMRS used for estimating a downlink channel to demodulate the PDSCH, wherein the downlink channel estimated by using the second DMRS is estimated based on an assumption that a same precoder is applied to the one or more second RB pairs. ### Claim 7 A downlink reception entity for performing downlink reception, the downlink reception entity comprising: a reception module configured to receive a downlink signal from a downlink transmission entity; a transmission module configured to transmit an uplink signal to the downlink transmission entity; and a processor configured to control the reception module and the transmission module, wherein the processor is further configured to: receive, through the reception module, downlink control information by demodulating a Physical Downlink Control Channel (PDCCH) in a first resource block (RB) pair within an RB bundle based on a downlink channel estimated by using a first Demodulation Reference Signal (DMRS) in the first RB pair; and receive, through the reception module, downlink data by demodulating a Physical Downlink Shared Channel (PDSCH) in one or more second RB pairs within the RB bundle based on a downlink channel estimated by using a second DMRS in the one or more second RB pairs, wherein the downlink channel estimated by using the second DMRS is estimated based on an assumption that a same precoder is applied to the one or more second RB pairs. ### Claim 8 A downlink transmission entity for performing downlink transmission in a wireless communication system, the downlink transmission entity comprising: a reception module configured to receive an uplink signal from a downlink reception entity; a transmission module configured to transmit a downlink signal to the downlink reception entity; and a processor configured to control the reception module and the transmission module, wherein the processor is further configured to: transmit, through the transmission module, in a first resource block (RB) pair within an RB bundle, downlink control information through a Physical Downlink Control Channel (PDCCH) and a first Demodulation Reference Signal (DMRS) used for estimating a downlink channel to demodulate the PDCCH; and transmit, through the transmission module, in one or more second RB pairs within the RB bundle, downlink data through a Physical Downlink Shared Channel (PDSCH) and a second DMRS used for estimating a downlink channel to demodulate the PDSCH, wherein the downlink channel estimated by using the second DMRS is estimated based on an assumption that a same precoder is applied to the one or more second RB pairs.