# US 2018/0323897 A1 · Scrambling initialisation in a communications system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0323897 A1 - Document ID: US20180323897A1 - Status: Published application - Kind: A1 - Application number: 15/773,310 - Filed: 2016-11-01 - Published: 2018-11-08 - Earliest claimed: 2015-11-06 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Robert ARNOTT; Yassin Aden AWAD; Caroline LIANG - Web page: https://patentgrep.com/patent/US20180323897A1 ## CPC - H04J 13/10: Code generation - H04J 13/0022: {PN, e.g. Kronecker} - H04J 13/0025: {M-sequences} - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H04W 8/26: Network addressing or numbering for mobility support - H04W 72/0466: {the resource being a scrambling code} - 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) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Scrambling code is initialized based on a parameter, n′RNTl, that changes from a given block of sub-frames to a subsequent block of sub-frames wherein the parameter is derived using one of the following formulas: n′RNTl=(nRNTI+SFN)mod 216 n′RNTl=(nRNTI+k)mod 216 where nRNTI is a temporary identifier associated with a mobile device connected to said cell and for which said scrambling code is applicable; and SFN is a system frame number associated with said at least one of said sequence of sub-frames; and k is a sub-frame counter. ## Claims ### Claim 1 Communication apparatus for a cellular communication system comprising a plurality of cells, the communication apparatus comprising: means for communicating signals in a cell in a sequence of sub-frames; and means for scrambling said signals communicated in said cell using a scrambling sequence that is applied per sub-frame for a Physical Downlink Shared Channel (PDSCH) for a given block of sub-frames; wherein said scrambling sequence is initialized based on a parameter that changes from one block of sub-frames to a next block of sub-frames and a sub-frame number. ### Claim 2 (depends on 1) The communication apparatus according to claim 1, wherein said parameter is derived based on at least one of: a system frame number associated with at least one of said sequence of sub-frames; and a counter associated with said block of sub-frames. ### Claim 3 (depends on 1) The communication apparatus according to claim 1, wherein said parameter is derived using the following formula: n′RNTI=(nRNTI+SFN)mod 216 where n′RNTI is said parameter, nRNTI is a temporary identifier associated with a mobile device connected to said cell and for which said scrambling sequence is applicable; and SFN is a system frame number associated with said at least one of said sequence of sub-frames. ### Claim 4 (depends on 1) The communication apparatus according to claim 1, wherein said parameter is derived using the following formula: n′RNTI=(nRNTI+k)mod 216 where n′RNTI is said parameter, nRNTI is a temporary identifier associated with a mobile device connected to said cell and for which said scrambling sequence is applicable; and k is a sub-frame counter. ### Claim 5 (depends on 4) The communication apparatus according to claim 4, wherein said parameter is derived by incrementing said sub-frame counter upon each repetition of a particular signal. ### Claim 6 (depends on 4) The communication apparatus according to claim 4, wherein said sub-frame counter is reset to a default value (e.g. ‘0’) when at least one of the following occurs: said particular signal is being communicated for the first time; and said sub-frame counter reaches an associated maximum value. ### Claim 7 (depends on 1) The communication apparatus according to claim 1, wherein said scrambling sequence is derived using at least one of the following formulas: cinit=n′RNTI214+q·213+└ns/2┘·29+NIDcell [Math. 1] and cinit=230+n′RNTI·214+q·213+└ns/2┘·29+NIDcell [Math. 2] where cinit is an initial scrambling code for said scrambling sequence; n′RNTI is the parameter q is a codeword index; ns is a slot number associated with said sequence of sub-frames; NIDcell [Math. 3] is a unique identifier for said cell; and └x┘ [Math. 4] is a flooring function (i.e. the largest integer not greater than ‘x’). ### Claim 8 (depends on 1) The communication apparatus according to claim 1, wherein said scrambling means is configured to: scramble said signals using a scrambling code upon transmission by said communicating means; and/or de-scramble said signals using said scrambling code upon reception by said communicating means. ### Claim 9 (depends on 1) The communication apparatus according to claim 1, wherein each block of sub-frames comprises ten sub-frames. ### Claim 10 (depends on 1) The communication apparatus according to claim 1, comprising at least one of: a base station; a mobile (cellular) telephone; and a machine-type communication (MTC) device. ### Claim 11 (depends on 1) A system comprising the communication apparatus according to claim 1, the communication apparatus forming part of at least one of a base station and a mobile communication device. ### Claim 12 A method performed by communication apparatus configured to communicate signals, in a sequence of sub-frames, in a cell of cellular communication system comprising a plurality of cells, the method comprising: initializing a scrambling sequence based on a parameter that changes from one block of sub-frames to a next block of sub-frames and a sub-frame number, and scrambling signals communicated in said cell using a scrambling sequence that is applied per sub-frame for a Physical Downlink Shared Channel (PDSCH) for a given block of sub-frames. ### Claim 13 A computer program product comprising instructions for causing a computer-programmable device of a communication apparatus configured to communicate signals, in a sequence of sub-frames, in a cell of cellular communication system comprising a plurality of cells, to perform a method comprising: initializing a scrambling sequence based on a parameter that changes from one block of sub-frames to a next block of sub-frames and a sub-frame number, and scrambling signals communicated in said cell using a scrambling sequence that is applied per sub-frame for a Physical Downlink Shared Channel (PDSCH) for a given block of sub-frames. ### Claim 14 (depends on 13) The computer program product according to claim 13, wherein the method further comprises deriving said parameter based on at least one of: a system frame number associated with at least one of said sequence of sub-frames; and a counter associated with said block of sub-frames. ### Claim 15 (depends on 12) The method according to claim 12, comprising deriving said parameter based on at least one of: a system frame number associated with at least one of said sequence of sub-frames; and a counter associated with said block of sub-frames.