# US 9,438,322 B2 · Mobile station and reception method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,322 B2 - Document ID: US9438322B2 - Status: Granted - Kind: B2 - Application number: 14/830,527 - Filed: 2015-08-19 - Published: 2015-12-17 - Granted: 2016-09-06 - Earliest claimed: 2007-08-17 - Assignees: Sun Patent Trust - Applicants: Sun Patent Trust - Inventors: Seigo Nakao; Masayuki Hoshino; Atsushi Sumasu; Katsuhiko Hiramatsu - Web page: https://patentgrep.com/patent/US9438322B2 ## CPC - 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)} - H04B 7/0413: MIMO systems - H04B 7/0417: Feedback systems - H04B 7/0682: {using phase diversity (e.g. phase sweeping)} - H04L 5/0023: {Time-frequency-space} - H04L 25/0226: {sounding signals per se} - H04L 25/0228: {with direct estimation from sounding signals} - H04L 27/2613: {Structure of the reference signals} - H04L 27/2626: {Arrangements specific to the transmitter only} - H04W 74/002: {Transmission of channel access control information} - H04W 88/02: Terminal devices - H04W 88/08: Access point devices - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - 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 Provided is a radio communication device which can separate propagation paths of antenna ports and improve a channel estimation accuracy even when using virtual antennas. The device includes: a mapping unit which maps a data signal after modulation to a virtual antenna and a virtual antenna; a phase inversion unit which inverts the phase of S0 transmitted from an antenna port in synchronization with a phase inversion unit between the odd-number slot and the even-number slot; the phase inversion unit which inverts the phase of R0 transmitted from the antenna port; a phase inversion unit which inverts the phase of S1 transmitted from an antenna port in synchronization with a phase inversion unit; and the phase inversion unit which inverts the phase of R1 transmitted from an antenna port. ## Claims ### Claim 1 An integrated circuit to control a process, the process comprising: transmitting first reference signals on a plurality of first resource elements; transmitting second reference signals different from the first reference signals on a plurality of second resource elements, a number of the plurality of second resource elements in a resource block being less than a number of the plurality of first resource elements in the resource block, the first reference signals being associated with mobile stations of a first type and the second reference signals being associated with mobile stations of a second type, wherein: a first one of the second reference signals is multiplied by “1” and is transmitted via a first one of a pair of antenna ports; and a second one of the second reference signals is multiplied by “−1” and is transmitted via a second one of the pair of antenna ports. ### Claim 2 (depends on 1) The integrated circuit according to claim 1, comprising: circuitry which, in operation, controls the process; at least one input coupled to the circuitry, wherein the at least one input, in operation, inputs data; and at least one output coupled to the circuity, wherein the at least one output, in operation, outputs data. ### Claim 3 (depends on 2) The integrated circuit according to claim 2, wherein the mobile stations of the first type support base station configurations of up to four antenna ports, and the mobile stations of the second type support base station configurations of up to eight antenna ports. ### Claim 4 (depends on 2) The integrated circuit according to claim 2, wherein the mobile stations of the first type are configured to support LTE, and the mobile stations of the second type are configured to support LIE-Advanced. ### Claim 5 (depends on 2) The integrated circuit according to claim 2, wherein a phase of the second reference signal of the second reference signals is reversed relative to a phase of the first reference signal of the second reference signals. ### Claim 6 (depends on 2) The integrated circuit according to claim 2, wherein prior to multiplication, the first and second reference signals of the second reference signals are identical. ### Claim 7 (depends on 2) The integrated circuit according to claim 2, wherein the first reference signals are used for both downlink channel quality estimation and downlink power measurement, and the second reference signals are used for downlink channel quality estimation. ### Claim 8 (depends on 2) The integrated circuit according to claim 2, wherein a number of resource elements for the first reference signals transmitted per antenna port is greater than a number of resource elements for the second reference signals transmitted per antenna port. ### Claim 9 (depends on 2) The integrated circuit according to claim 2, wherein a number of antenna ports which are configured for a mobile station corresponds to which one or both of the first reference signals and the second reference signals are used by the mobile station for channel quality estimation. ### Claim 10 (depends on 2) The integrated circuit according to claim 2, wherein: the first reference signals are associated with the mobile stations of first type and with the mobile stations of the second type; and the second reference signals are only associated with the mobile stations of the second type. ### Claim 11 (depends on 2) The integrated circuit according to claim 2, wherein the at feast one output and the at least one input, in operation, are coupled to an antenna. ### Claim 12 (depends on 9) The integrated circuit according to claim 9, wherein the number of antenna ports configured for the mobile station is 4 or less in correspondence with a case where the first reference signals are used for channel quality estimation, and the number of antenna ports configured for the mobile station is 8 in correspondence with a case where the second reference signals are used for channel quality estimation. ### Claim 13 An integrated circuit comprising circuitry, which, in operation: controls transmission of first reference signals on a plurality of first resource elements; controls transmission of second reference signals different from the first reference signals on a plurality of second resource elements, a number of the plurality of second resource elements in a resource block being less than a number of the plurality of first resource elements in the resource block, the first reference signals being associated with mobile stations of a first type and the second reference signals being associated with mobile stations of a second type, wherein: a first one of the second reference signals is multiplied by “1” and is transmitted via a first one of a pair of antenna ports; and a second one of the second reference signals is multiplied by “−1” and is transmitted via a second one of the pair of antenna ports. ### Claim 14 (depends on 13) The integrated circuit according to claim 13, further comprising: at least one input coupled to the circuitry; and at least one output coupled to the circuity, wherein the at least one output, in operation, outputs data. ### Claim 15 (depends on 14) The integrated circuit according to claim 14, wherein the mobile stations of the first type support base station configurations of up to four antenna ports, and the mobile stations of the second type support base station configurations of up to eight antenna ports. ### Claim 16 (depends on 14) The integrated circuit according to claim 14, wherein the mobile stations of the first type are configured to support LTE, and the mobile stations of the second type are configured to support LTE-Advanced. ### Claim 17 (depends on 14) The integrated circuit according to claim 14, wherein a phase of the second reference signal of the second reference signals is reversed relative to a phase of the first reference signal of the second reference signals. ### Claim 18 (depends on 14) The integrated circuit according to claim 14, wherein prior to multiplication, the first and second reference signals of the second reference signals are identical. ### Claim 19 (depends on 14) The integrated circuit according to claim 14, wherein the first reference signals are used for both downlink channel quality estimation and downlink power measurement, and the second reference signals are used for downlink channel quality estimation. ### Claim 20 (depends on 14) The integrated circuit according to claim 14, wherein a number of resource elements for the first reference signals transmitted per antenna port is greater than a number of resource elements for the second reference signals transmitted per antenna port. ### Claim 21 (depends on 14) The integrated circuit according to claim 14, wherein a number of antenna ports which are configured for a mobile station corresponds to which one or both of the first reference signals and the second reference signals are used by the mobile station for channel quality estimation. ### Claim 22 (depends on 14) The integrated circuit according to claim 14, wherein: the first reference signals are associated with the mobile stations of first type and with the mobile stations of the second type; and the second reference signals are only associated with the mobile stations of the second type. ### Claim 23 (depends on 14) The integrated circuit according to claim 14, wherein the at least one output and the at least one input, in operation, are coupled to an antenna. ### Claim 24 (depends on 21) The integrated circuit according to claim 21, wherein the number of antenna ports configured for the mobile station is 4 or less in correspondence with a case where the first reference signals are used for channel quality estimation, and the number of antenna ports configured for the mobile station is 8 in correspondence with a case where the second reference signals are used for channel quality estimation.