# US 2021/0345327 A1 · DMRS with Shortened Scheduling > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0345327 A1 - Document ID: US20210345327A1 - Status: Published application - Kind: A1 - Application number: 17/378,275 - Filed: 2021-07-16 - Published: 2021-11-04 - Earliest claimed: 2015-03-09 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Niklas ANDGART; Helka-Liina MÄÄTTANEN - Web page: https://patentgrep.com/patent/US20210345327A1 ## CPC - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - 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} - H04W 8/02: Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks - H04W 72/12: Wireless traffic scheduling - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract According to some embodiments, a network node is operable to separately schedule radio transmissions per sub-subframe (SSF). A method in the network node comprises mapping a first demodulation reference signal (DMRS) to first resource elements in a first SSF. The first resource elements are associated with a first set of antenna ports. The method includes mapping a second DMRS to second resource elements in a second SSF. The second resource elements are associated with the first set of one or more antenna ports and precoding of the second DMRS differs from a precoding of the first DMRS. The method further includes scheduling a radio transmission during the first SSF precoded in accordance with the first DMRS, and scheduling a radio transmission during the second SSF precoded in accordance with the second DMRS. In particular embodiments, a subframe may comprise two, four, or eight sub-subframes. ## Claims ### Claim 1 A method in a network node of a wireless communication network, the network node operable to separately schedule radio transmissions per sub-subframe (SSF), the method comprising: mapping a first demodulation reference signal (DMRS) to one or more first resource elements in a first SSF, the one or more first resource elements associated with a first set of one or more antenna ports; mapping a second DMRS to one or more second resource elements in a second SSF, the one or more second resource elements associated with the first set of one or more antenna ports, and a precoding of the second DMRS differs from a precoding of the first DMRS; scheduling a first radio transmission during the first SSF precoded in accordance with the first DMRS; scheduling a second radio transmission during the second SSF precoded in accordance with the second DMRS; and transmitting the scheduled first and second radio transmissions. ### Claim 2 (depends on 1) The method of claim 1, wherein the first SSF and the second SSF together comprise one subframe. ### Claim 3 (depends on 1) The method of claim 1, further comprising: mapping a third DMRS to one or more third resource elements in the first SSF, the one or more third resource elements associated with a second set of one or more antenna ports; mapping a fourth DMRS to one or more fourth resource elements in the second SSF, the one or more fourth resource elements associated with the second set of one or more antenna ports; scheduling a third radio transmission during a third SSF precoded in accordance with the third DMRS; scheduling a fourth radio transmission during a fourth SSF precoded in accordance with the fourth DMRS; and transmitting the scheduled third and fourth radio transmissions. ### Claim 4 (depends on 3) The method of claim 3, wherein the first SSF, the second SSF, the third SSF, and the fourth SSF together comprise one subframe. ### Claim 5 (depends on 3) The method of claim 3, wherein scheduling the radio transmission during the third SSF precoded in accordance with the third DMRS or scheduling the radio transmission during the fourth SSF precoded in accordance with the fourth DMRS comprises scheduling the radio transmission to a wireless device with a low mobility. ### Claim 6 A method in a wireless device of a wireless communication network, the wireless device operable to receive radio transmissions scheduled separately per sub-subframe (SSF), the method comprising: receiving a first demodulation reference signal (DMRS) mapped to one or more first resource elements in a first SSF, the one or more first resource elements associated with a first set of one or more antenna ports; receiving a radio transmission precoded in accordance with the first DMRS; and wherein a subframe comprises the first SSF and a second SSF, the second SSF comprises a DMRS mapped to one or more second resource elements in the second SSF, the one or more second resource elements associated with the first set of one or more antenna ports. ### Claim 7 (depends on 6) The method of claim 6, wherein the received radio transmission precoded in accordance with the first DMRS is received during the first SSF. ### Claim 8 (depends on 6) The method of claim 6, wherein the received radio transmission precoded in accordance with the first DMRS is received during a third SSF. ### Claim 9 (depends on 6) The method of claim 6, wherein the first SSF comprises one SSF of a subframe comprising two SSFs. ### Claim 10 (depends on 8) The method of claim 8, wherein the first SSF and the third SSF comprise two SSFs of a subframe comprising four SSFs. ### Claim 11 (depends on 8) The method of claim 8, wherein the wireless device comprises a wireless device with a low mobility. ### Claim 12 A network node operable to separately schedule radio transmissions per sub-subframe (SSF), the network node comprising a processor operable to: map a first demodulation reference signal (DMRS) to one or more first resource elements in a first SSF, the one or more first resource elements associated with a first set of one or more antenna ports; map a second DMRS to one or more second resource elements in a second SSF, the one or more second resource elements associated with the first set of one or more antenna ports, and a precoding of the second DMRS differs from a precoding of the first DMRS; schedule a first radio transmission during the first SSF precoded in accordance with the first DMRS; schedule a second radio transmission during the second SSF precoded in accordance with the second DMRS; and transmit the scheduled first and second radio transmissions. ### Claim 13 (depends on 12) The network node of claim 12, wherein the first SSF and the second SSF together comprise one subframe. ### Claim 14 (depends on 12) The network node of claim 12, the processor further operable to: map a third DMRS to one or more third resource elements in the first SSF, the one or more third resource elements associated with a second set of one or more antenna ports; map a fourth DMRS to one or more fourth resource elements in the second SSF, the one or more fourth resource elements associated with the second set of one or more antenna ports; schedule a third radio transmission during a third SSF precoded in accordance with the third DMRS; schedule a fourth radio transmission during a fourth SSF precoded in accordance with the fourth DMRS; and transmit the scheduled third and fourth radio transmissions. ### Claim 15 (depends on 14) The network node of claim 14, wherein the first SSF, the second SSF, the third SSF, and the fourth SSF together comprise one subframe. ### Claim 16 (depends on 14) The network node of claim 14, the processor operable to schedule the radio transmission during the third SSF or the radio transmission during the fourth SSF to a wireless device with a low mobility. ### Claim 17 A wireless device operable to receive radio transmissions scheduled separately per sub-subframe (SSF), the wireless device comprising a processor operable to: receive a first demodulation reference signal (DMRS) mapped to one or more first resource elements in a first SSF, the one or more first resource elements associated with a first set of one or more antenna ports; and receive a radio transmission precoded in accordance with the first DMRS; and wherein a subframe comprises the first SSF and a second SSF, the second SSF comprises a DMRS mapped to one or more second resource elements in the second SSF, the one or more second resource elements associated with the first set of one or more antenna ports. ### Claim 18 (depends on 17) The wireless device of claim 17, wherein the received radio transmission precoded in accordance with the first DMRS is received during the first SSF. ### Claim 19 (depends on 17) The wireless device of claim 17, wherein the received radio transmission precoded in accordance with the first DMRS is received during a third SSF. ### Claim 20 (depends on 17) The wireless device of claim 17, wherein the first SSF comprises one SSF of a subframe comprising two SSFs. ### Claim 21 (depends on 19) The wireless device of claim 19, wherein the first SSF and the third SSF comprise two SSFs of a subframe comprising four SSFs. ### Claim 22 (depends on 19) The wireless device of claim 19, wherein the wireless device comprises a wireless device with a low mobility.