# US 2018/0323912 A1 · Methods and Apparatuses for Signaling in Dynamic Time Division Duplex Systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323912 A1 - Document ID: US20180323912A1 - Status: Published application - Kind: A1 - Application number: 16/022,865 - Filed: 2018-06-29 - Published: 2018-11-08 - Earliest claimed: 2013-05-10 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Erik Eriksson; Xinghua Song - Web page: https://patentgrep.com/patent/US20180323912A1 ## CPC - H04L 1/1854: {Scheduling and prioritising arrangements} - H04L 1/0006: {by adapting the transmission format} - H04L 1/0025: {Transmission of mode-switching indication} - H04L 1/0027: {Scheduling of signalling, e.g. occurrence thereof} - H04L 1/1812: Hybrid protocols; Hybrid automatic repeat request [HARQ] - H04L 5/22: using time-division multiplexing - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04W 76/28: Discontinuous transmission [DTX]; Discontinuous reception [DRX] - H04W 84/042: {Public Land Mobile systems, e.g. cellular systems} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present invention relates to a method in a UE served by a network node, a method in the network node, the UE, and the network node. The network node is applying dynamic TDD with flexible subframes. The method comprises receiving a first configuration message from the network node indicating a TDD reference configuration, and determining in which subframe to signal HARQ information based on the TDD reference configuration. The method further comprises receiving a second configuration message from the network node indicating a set of DL subframes that may comprise explicit signaling messages, monitoring the indicated set of DL subframes, and receiving an explicit signaling message in response to monitoring. The explicit signaling message designates a subframe in which the UE shall receive a DL signal. The method also comprises preparing to receive the DL signal in the designated subframe. ## Claims ### Claim 1 A method for enabling a user equipment served by a network node to determine a subframe in which to receive a downlink signal, the method being performed by the network node in a dynamic Time Division Duplex (TDD) wireless communication system where at least one subframe is a flexible subframe assigned as either a downlink subframe or an uplink subframe, the method comprising: transmitting a configuration message to the user equipment indicating a fixed downlink subframe that comprises an explicit signaling message, wherein the explicit signaling message designates a subframe in which the user equipment should receive the downlink signal and wherein a fixed downlink subframe is designated for downlink transmissions only; and transmitting the explicit signaling message in the indicated fixed downlink subframe. ### Claim 2 (depends on 1) The method of claim 1, wherein the configuration message indicates a TDD reference configuration. ### Claim 3 (depends on 1) The method of claim 1, further comprising transmitting the downlink signal in the designated subframe. ### Claim 4 (depends on 1) The method of claim 1, wherein the downlink signal is a signal for measuring Channel Status Information (CSI). ### Claim 5 (depends on 1) The method of claim 1, wherein the downlink signal comprises a downlink control channel to be received by the user equipment. ### Claim 6 (depends on 1) The method of claim 1, wherein the configuration message indicates a set of fixed downlink subframes one of which comprises the explicit signaling message. ### Claim 7 (depends on 6) The method of claim 6, wherein the configuration message indicates the set of fixed downlink subframes using a subframe offset or a periodicity. ### Claim 8 (depends on 1) The method of claim 1, wherein the configuration message indicates a radio network temporary identifier associated with the user equipment. ### Claim 9 (depends on 1) The method of claim 1: wherein the wireless communication system is a Long Term Evolution (LTE) system; and wherein the explicit signaling message is transmitted in a common search space on a physical downlink control channel (PDCCH). ### Claim 10 (depends on 1) The method of claim 1, wherein the designation in the explicit signaling message is applied a fixed time after the transmission of the explicit signaling message. ### Claim 11 A method for determining a subframe in which to receive a downlink signal, the method being performed by a user equipment served by a network node in a dynamic Time Division Duplex (TDD) wireless communication system where at least one subframe is a flexible subframe assigned as either a downlink subframe or an uplink subframe, the method comprising: receiving a configuration message from the network node indicating a fixed downlink subframe that comprises an explicit signaling message, wherein the explicit signaling message designates a subframe in which the user equipment should receive the downlink signal and wherein a fixed downlink subframe is designated for downlink transmissions only; and receiving the explicit signaling message in the designated subframe. ### Claim 12 (depends on 11) The method of claim 11, wherein the configuration message is a TDD reference configuration. ### Claim 13 (depends on 12) The method of claim 12, wherein the method further comprises determining in which subframe to signal HARQ information based on the TDD reference configuration. ### Claim 14 (depends on 11) The method of claim 11, wherein the method further comprises receiving the downlink signal in the designated subframe. ### Claim 15 (depends on 11) The method of claim 11, wherein the method further comprises using the downlink signal to measure Channel Status Information (CSI). ### Claim 16 (depends on 11) The method of claim 11, wherein the downlink signal comprises a downlink control channel. ### Claim 17 (depends on 11) The method of claim 11, wherein the configuration indicates a set of fixed downlink subframes one of which comprises the explicit signaling message. ### Claim 18 (depends on 17) The method of claim 17, further comprising turning off at least one of a radio front end and base band processing in subframes other than one or more designated subframes designated in one or more explicit signaling messages of the set of fixed downlink subframes. ### Claim 19 (depends on 17) The method of claim 17, wherein the configuration indicates the set of fixed downlink subframes using a subframe offset or a periodicity. ### Claim 20 (depends on 17) The method of claim 17, wherein the method further comprises monitoring the indicated set of fixed downlink subframes for the explicit signaling message only when the user equipment is in a discontinuous reception (DRX) active mode. ### Claim 21 (depends on 17) The method of claim 17, further comprising, when no explicit signaling message is received when monitoring of the indicated set of fixed downlink subframes for the explicit signaling message, receiving the downlink signal in a subframe according to a fallback configuration until a next occasion for monitoring for any explicit signaling messages. ### Claim 22 (depends on 1) The method of claim 1: wherein the configuration message comprises a radio network temporary identifier; and wherein the configuration message is received when the radio network temporary identifier is associated with the user equipment. ### Claim 23 (depends on 1) The method of claim 1: wherein the wireless communication system is a Long Term Evolution (LTE) system; and wherein the explicit signaling message is received in a common search space of a physical downlink control channel (PDCCH). ### Claim 24 (depends on 11) The method of claim 11, wherein the designation in the explicit signaling message is applied a fixed time after receiving the explicit signaling message. ### Claim 25 A network node for enabling a user equipment served by the network node to determine a subframe in which to receive a downlink signal, the network node comprising: a processor and a memory, the memory containing instructions executable by the processor whereby the network node is configured to: operate in a dynamic Time Division Duplex (TDD) system where at least one subframe of a plurality of subframes is a flexible subframe assigned as either a downlink subframe or an uplink; transmit a configuration message to the user equipment indicating of the plurality of subframes a fixed downlink subframe that comprises an explicit signaling message, wherein the explicit signaling message designates a subframe in which the user equipment should receive the downlink signal and wherein a fixed downlink subframe is designated for downlink transmissions only and wherein the subframes; and transmit the explicit signaling message in the indicated fixed downlink subframe. ### Claim 26 A user equipment for determining a subframe in which to receive a downlink signal, the user equipment comprising: a processor and a memory, the memory containing instructions executable by the processor whereby the user equipment is configured to: operate in a dynamic Time Division Duplex (TDD) system where at least one subframe of a plurality of subframes is a flexible subframe assigned as either a downlink subframe or an uplink; receive a configuration message from the network node indicating of the plurality of subframes a fixed downlink subframe that comprises an explicit signaling message, wherein the explicit signaling message designates a subframe in which the user equipment should receive the downlink signal and wherein a fixed downlink subframe is designated for downlink transmissions only; and receive the explicit signaling message in the designated subframe.