# US 2017/0289999 A9 · Methods, systems and devices for decoupled interference randomization for uplink reference signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0289999 A9 - Document ID: US20170289999A9 - Status: Published application - Kind: A9 - Application number: 14/790,108 - Filed: 2015-07-02 - Published: 2017-10-05 - Earliest claimed: 2012-05-23 - Assignees: Telefonaktiebolaget L M Ericsson (publ) - Applicants: Telefonaktiebolaget L M Ericsson (publ) - Inventors: Stefano Sorrentino - Web page: https://patentgrep.com/patent/US20170289999A9 ## CPC - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04J 11/0026: {of multi-user interference} - H04J 11/005: {of intercell interference} - H04J 13/0062: {Zadoff-Chu} - 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 5/0073: {Allocation arrangements that take into account other cell interferences} - H04W 72/21: in the uplink direction of a wireless link, i.e. towards the network - H04W 72/541: using the level of interference - H04J 2211/005: Long term evolution [LTE] - H04L 5/0012: {Hopping in multicarrier systems} - H04L 5/0016: {Time-frequency-code} - H04L 5/0035: {Resource allocation in a cooperative multipoint environment} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Interference between reference signals from user equipments in a wireless network, the method may be reduced by using a received time shift value from a node in the wireless network. An interference randomization technique may be applied to a reference signal and a sequence may be generated based on the reference signal to which the interference randomization technique has been applied. A processed reference signal may be derived by applying a time shift based on the time shift value to the sequence. The processed reference signal may be transmitted to the node. Related systems, methods, nodes and wireless devices are also described. ## Claims ### Claim 1 A node of a wireless communication network comprising: a wireless transceiver; and a processor that is configured to perform operations comprising: determining a time shift to be applied by a user equipment to a sequence generated based on applying an interference randomization technique to a reference signal; and communicating from the node the time shift that was determined to the user equipment. ### Claim 2 (depends on 1) The node according to claim 1, wherein the node is a first node and the reference signal is a first reference signal, wherein determining the time shift further comprises: coordinating determination of the time shift with a second node in the wireless communication network such that the first reference signal to which the time shift is applied is orthogonal to a second reference signal received by the second node. ### Claim 3 (depends on 2) The node according to claim 2, wherein the user equipment is a first user equipment, wherein the first reference signal is received from the first user equipment associated with the first node and the second reference signal is received from a second user equipment associated with the second node. ### Claim 4 (depends on 2) The node according to claim 2, wherein the processor is further configured to perform operations comprising: collecting information related to one or more time shifts respectively associated with one or more user equipment potentially mutually interfering with the first user equipment. ### Claim 5 (depends on 1) The node according to claim 1, wherein the processor is further configured to perform operations comprising: receiving a processed reference signal from the first user equipment, wherein the processed reference signal is associated with the sequence to which the time shift has been applied; and estimating an uplink channel associated with the first user equipment based on the received processed reference signal. ### Claim 6 (depends on 1) The node according to claim 1, wherein the time shift comprises an integer number of time slots, frames and/or subframes. ### Claim 7 (depends on 1) The node according to claim 1, wherein the reference signal comprises a Physical Uplink Shared Channel (PUSCH) Demodulation Reference Signal (DMRS), a Physical Uplink Control Channel (PUCCH) DMRS, or a Sounding Reference Signal (SRS). ### Claim 8 (depends on 1) The node according to claim 1, wherein the interference randomization technique comprises Cyclic Shift Hopping (CSH) or Sequence Group Hopping (SGH). ### Claim 9 (depends on 1) The node according to claim 1, wherein communicating the time shift to the user equipment comprises communicating the time shift using Radio Resource Control (RRC) signaling in a UE-specific fashion or in a cell-specific fashion.