# US 9,521,020 B2 · Data packet processing for estimation of a direction towards a transmitter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,521,020 B2 - Document ID: US9521020B2 - Status: Granted - Kind: B2 - Application number: 14/624,701 - Filed: 2015-02-18 - Published: 2015-06-11 - Granted: 2016-12-13 - Earliest claimed: 2015-02-18 - Assignees: Nokia Technologies Oy - Applicants: Nokia Technologies Oy - Inventors: Antti Paavo Tapani Kainulainen; Ilari Aleksi Teikari; Ville Valtteri Ranki - Web page: https://patentgrep.com/patent/US9521020B2 ## CPC - H04L 25/03866: {using scrambling} - G01S 3/16: using amplitude comparison of signals derived sequentially from receiving antennas or antenna systems having differently-oriented directivity characteristics or from an antenna system having periodically-varied orientation of directivity characteristic - H04B 1/10: Means associated with receiver for limiting or suppressing noise or interference - H04B 7/0814: {based on current reception conditions, e.g. switching to different antenna when signal level is below threshold} - H04B 7/086: {using weights depending on external parameters, e.g. direction of arrival [DOA], predetermined weights or beamforming} - H04L 25/0204: {of multiple channels} - H04L 25/08: Modifications for reducing interference; Modifications for reducing effects due to line faults {; Receiver end arrangements for detecting or overcoming line faults} - H04W 4/80: Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract It is disclosed to insert an anti-whitened data block, which is obtainable from a specific data block by anti-whitening, into a data block that is to be whitened by a whitening to yield a whitened data block, wherein the anti-whitening compensates the whitening so that the whitened data block will comprise the specific data block in non-whitened form. It is further disclosed to output, in a first operating mode, an output data block generated by one of whitening and de-whitening an input data block in its entirety, and outputting, in a second operating mode, one of: an output data block generated by one of whitening and de-whitening all parts of an input data block under exclusion of a specific data block contained in the input data block. ## Claims ### Claim 1 An apparatus comprising: at least one processor, and at least one memory including program code, the at least one memory and the program code configured to with the at least one processor, cause the apparatus at least: to insert an anti-whitened data block, which is obtainable from a specific data block by anti-whitening, into a data block that is to be whitened by a whitening to yield a whitened data block, wherein said anti-whitening compensates said whitening so that said whitened data block will comprise said specific data block in non-whitened form, and wherein said specific data block is designed to be used by a receiver of said whitened data block to estimate a direction towards a transmitter of said whitened data block based on a received representation of said specific data block. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein said received representation of said specific data block is affected by switching through antennas of a single-channel multi-antenna transmitter during a transmission of said specific data block and/or by switching through antennas of a single-channel multi-antenna receiver during a reception of said specific data block. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein said at least one processor and a further processor, and said at least one memory including program code, cause the apparatus to perform at least one of said anti-whitening on said specific data block to obtain said anti-whitened data block and said whitening on said data block that is to be whitened to obtain said whitened data block. ### Claim 4 (depends on 1) The apparatus according to claim 1, wherein said data block that is to be whitened comprises information on said specific data block. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein said anti-whitening and said whitening are based on linear feedback shift registers with the same length, feedback and initialization. ### Claim 6 (depends on 1) The apparatus according to claim 1, wherein said apparatus is an apparatus that comprises an antenna or a communication device that comprises an antenna. ### Claim 7 An apparatus comprising: an input configured to receive input data blocks; at least one processor, and at least one memory including program code, the at least one memory and the program code configured to with the at least one processor, cause the apparatus at least: to output, in a first operating mode, an output data block generated by whitening or de-whitening one of said input data blocks, which does not comprise a specific data block, in its entirety, and to output, in a second operating mode an output data block generated by whitening or de-whitening all parts of one of said input data blocks, which comprises said specific data block, under exclusion of said specific data block, so that said output data block comprises said specific data block in unchanged form, wherein said specific data block is designed to be used by a receiver of said output data block to estimate a direction towards a transmitter of said output data block based on a received representation of said specific data block. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein said received representation of said specific data block is affected by switching through antennas of a single-channel multi-antenna transmitter during a transmission of said specific data block and/or switching through antennas of a single-channel multi-antenna receiver during a reception of said specific data block. ### Claim 9 (depends on 7) The apparatus according to claim 7, wherein said one of said input data blocks received in said second operating mode comprises information on said specific data block. ### Claim 10 (depends on 7) The apparatus according to claim 7, wherein said apparatus is an apparatus that comprises an antenna or a communication device that comprises an antenna. ### Claim 11 (depends on 7) The apparatus according to claim 7, wherein said input data block comprises a Protocol Data Unit (PDU) part and a Cyclic Redundancy Check (CRC) part of a Bluetooth packet. ### Claim 12 (depends on 1) The apparatus according to claim 1, wherein said anti-whitened data block is inserted into only a part of said data block that is to be whitened. ### Claim 13 (depends on 1) The apparatus according to claim 1, wherein said data block that is to be whitened comprises a Protocol Data Unit part and a Cyclic Redundancy Check part of a Bluetooth packet, and wherein said anti-whitened data block is inserted into at least a part of said PDU part. ### Claim 14 A method comprising: inserting an anti-whitened data block, which is obtainable from a specific data block by anti-whitening, into a data block that is to be whitened by a whitening to yield a whitened data block, wherein said anti-whitening compensates said whitening so that said whitened data block will comprise said specific data block in non-whitened form, and wherein said specific data block is designed to be used by a receiver of said whitened data block to estimate a direction towards a transmitter of said whitened data block based on a received representation of said specific data block. ### Claim 15 (depends on 14) The method according to claim 14, wherein said received representation of said specific data block is affected by switching through antennas of a single-channel multi-antenna transmitter during a transmission of said specific data block and/or by switching through antennas of a single-channel multi-antenna receiver during a reception of said specific data block. ### Claim 16 (depends on 14) The method according to claim 14, wherein said anti-whitened data block is inserted into only a part of said data block that is to be whitened. ### Claim 17 (depends on 14) The method according to claim 14, wherein said data block that is to be whitened comprises a Protocol Data Unit part and a Cyclic Redundancy Check part of a Bluetooth packet, and wherein said anti-whitened data block is inserted into at least a part of said PDU part. ### Claim 18 (depends on 1) The apparatus according to claim 1, wherein said whitening is also performed on said anti-whitened data block inserted into said data block. ### Claim 19 (depends on 14) The method according to claim 14, wherein said whitening is also performed on said anti-whitened data block inserted into said data block. ### Claim 20 A method comprising: receiving input data blocks; outputting, in a first operating mode, an output data block generated by whitening or de-whitening one of said input data blocks, which does not comprise a specific data block, in its entirety, and outputting, in a second operating mode, an output data block generated by whitening or de-whitening all parts of one of said input data blocks, which comprises said specific data block, under exclusion of said specific data block, so that said output data block comprises said specific data block in unchanged form, wherein said specific data block is designed to be used by a receiver of said output data block to estimate a direction towards a transmitter of said output data block based on a received representation of said specific data block. ### Claim 21 (depends on 20) The method according to claim 20, wherein said received representation of said specific data block is affected by switching through antennas of a single-channel multi-antenna transmitter during a transmission of said specific data block and/or switching through antennas of a single-channel multi-antenna receiver during a reception of said specific data block. ### Claim 22 (depends on 20) The method according to claim 20, wherein said one of said input data blocks received in said second operating mode comprises information on said specific data block. ### Claim 23 (depends on 20) The method according to claim 20, wherein said input data block comprises a Protocol Data Unit (PDU) part and a Cyclic Redundancy Check (CRC) part of a Bluetooth packet. ### Claim 24 A computer program product comprising a non-transitory computer readable storage medium encoded with instructions that, when executed by a processor, causes an apparatus at least to perform: receiving input data blocks; outputting, in a first operating mode, an output data block generated by whitening or de-whitening one of said input data blocks, which does not comprise a specific data block, in its entirety, and outputting, in a second operating mode, an output data block generated by whitening or de-whitening all parts of one of said input data blocks, which comprises said specific data block, under exclusion of said specific data block, so that said output data block comprises said specific data block in unchanged form, wherein said specific data block is designed to be used by a receiver of said output data block to estimate a direction towards a transmitter of said output data block based on a received representation of said specific data block. ### Claim 25 A computer program product comprising a non-transitory computer readable storage medium encoded with instructions that, when executed by a processor, causes an apparatus at least to perform: inserting an anti-whitened data block, which is obtainable from a specific data block by anti-whitening, into a data block that is to be whitened by a whitening to yield a whitened data block, wherein said anti-whitening compensates said whitening so that said whitened data block will comprise said specific data block in non-whitened form, and wherein said specific data block is designed to be used by a receiver of said whitened data block to estimate a direction towards a transmitter of said whitened data block based on a received representation of said specific data block.