# US 9,438,326 B2 · Method and apparatus for transmitting reference signal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,326 B2 - Document ID: US9438326B2 - Status: Granted - Kind: B2 - Application number: 14/626,055 - Filed: 2015-02-19 - Published: 2015-06-11 - Granted: 2016-09-06 - Earliest claimed: 2009-04-15 - Assignees: LG Electronics Inc. - Applicants: LG Electronics Inc. - Inventors: Jae Hoon Chung; Hyun Soo Ko; Moon Il Lee; Yeong Hyeon Kwon - Web page: https://patentgrep.com/patent/US9438326B2 ## CPC - H04B 7/0473: {taking constraints in layer or codeword to antenna mapping into account} - H04B 7/0678: {using different spreading codes between antennas (code allocation H04J13/16)} - H04B 7/0684: {using different training sequences per antenna} - H04J 13/004: {Orthogonal} - H04L 1/0027: {Scheduling of signalling, e.g. occurrence thereof} - 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 27/2627: {Modulators} - H04L 27/2653: {with direct demodulation of individual subcarriers} - H04W 40/244: {using a network of reference devices, e.g. beaconing} - H04W 72/04: Wireless resource allocation - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04W 72/0453: Resources in frequency domain, e.g. a carrier in FDMA - H04W 72/23: in the downlink direction of a wireless link, i.e. towards a terminal - H04B: TRANSMISSION - 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) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract The present invention relates to a wireless communication system, and more specifically, to a method and an apparatus for transmitting an RS (Reference Signal) from a transmission end. The present invention relates to an RS transmission method and an apparatus therefore, comprising the steps of: confirming RS resources which are defined according to each layer; and transmitting the precoded RS for the layers to a receiving end through a multiple antenna, wherein the RS resource includes a 1st index for indicating an RS resource pattern group in which the precoded RS is mapped within a resource block and a 2nd index for indicating a code resource for multiplexing the precoded RSs within the RS resource pattern group. ## Claims ### Claim 1 A method for transmitting signals by a communication apparatus in a wireless communication system, the method comprising: mapping, by the communication apparatus, a plurality of reference signals to one or more resource blocks; and transmitting, by the communication apparatus, the mapped plurality of reference signals on respective antenna ports of a first and second set of antenna ports, wherein each reference signal transmitted on the first set of antenna ports is code division multiplexed to a first group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, wherein each reference signal transmitted on the second set of antenna ports is code division multiplexed to a second group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, and wherein the first set of antenna ports comprises antenna ports {N, N+1, N+4, N+6} and the second set of antenna ports comprises antenna ports {N+2, N+3, N+5, N+7}. ### Claim 2 (depends on 1) The method according to claim 1, wherein the first group of resource elements or the second group of resource elements comprise three pairs of resource elements in one resource block, two resource elements in each of the three pairs are contiguous in a time domain, and two neighboring pairs of the three pairs are separated by at least four subcarriers in a frequency domain. ### Claim 3 (depends on 1) The method according to claim 1, wherein the first group of resource elements or the second group of resource elements is grouped as shown in the Table below: Even-numbered slot Odd-numbered slot l = M l = M + 1 l = M l = M + 1 k = 11 G0 G0 G0 G0 k = 10 G1 G1 G1 G1 k = 6 G0 G0 G0 G0 k = 5 G1 G1 G1 G1 k = 1 G0 G0 G0 G0 k = 0 G1 G1 G1 G1 where k represents a subcarrier index in a resource block, l represents an orthogonal frequency division multiplexing (OFDM) symbol index, M represents an integer of 0 to 5, G0 represents the first group of resource elements, and G1 represents the second group of resource elements. ### Claim 4 (depends on 1) The method according to claim 1, wherein each reference signal of the plurality of reference signals is multiplied by a corresponding orthogonal sequence in units of two or four neighboring resource elements with a same subcarrier index. ### Claim 5 (depends on 1) The method according to claim 1, wherein the plurality of reference signals are used for demodulation of a physical downlink shared channel (PDSCH). ### Claim 6 A method for receiving signals by a communication apparatus in a wireless communication system, the method comprising: receiving, by the communication apparatus, a plurality of reference signals in one or more resource blocks on respective antenna ports of a first and second set of antenna ports, wherein each reference signal received on the first set of antenna ports is code division de-multiplexed from a first group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, wherein each reference signal received on the second set of antenna ports is code division de-multiplexed from a second group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, and wherein the first set of antenna ports comprises antenna ports {N, N+1, N+4, N+6} and the second set of antenna ports comprises antenna ports {N+2, N+3, N+5, N+7}. ### Claim 7 (depends on 6) The method according to claim 6, wherein the first group of resource elements or the second group of resource elements comprise three pairs of resource elements in one resource block, two resource elements in each of the three pairs are contiguous in a time domain, and two neighboring pairs of the three pairs are separated by at least four subcarriers in a frequency domain. ### Claim 8 (depends on 6) The method according to claim 6, wherein the first group of resource elements or the second group of resource elements is grouped as shown in the Table below: Even-numbered slot Odd-numbered slot l = M l = M + 1 l = M l = M + 1 k = 11 G0 G0 G0 G0 k = 10 G1 G1 G1 G1 k = 6 G0 G0 G0 G0 k = 5 G1 G1 G1 G1 k = 1 G0 G0 G0 G0 k = 0 G1 G1 G1 G1 where k represents a subcarrier index in a resource block, l represents an orthogonal frequency division multiplexing (OFDM) symbol index, M represents an integer of 0 to 5, G0 represents the first group of resource elements, and G1 represents the second group of resource elements. ### Claim 9 (depends on 6) The method according to claim 6, wherein each reference signal of the plurality of reference signals is multiplied by a corresponding orthogonal sequence in units of two or four neighboring resource elements with a same subcarrier index. ### Claim 10 (depends on 6) The method according to claim 6, wherein the plurality of reference signals are used for demodulation of a physical downlink shared channel (PDSCH). ### Claim 11 A communication apparatus for transmitting signals in a wireless communication system, the communication apparatus comprising: a radio frequency (RF) unit; and a processor operatively connected to the RF unit and configured to: map a plurality of reference signals to one or more resource blocks, and transmit the mapped plurality of reference signals on respective antenna ports of a first and second set of antenna ports, wherein each reference signal transmitted on the first set of antenna ports is code division multiplexed to a first group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, wherein each reference signal transmitted on the second set of antenna ports is code division multiplexed to a second group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, and wherein the first set of antenna ports comprises antenna ports {N, N+1, N+4, N+6} and the second set of antenna ports comprises antenna ports {N+2, N+3, N+5, N+7}. ### Claim 12 (depends on 11) The communication apparatus according to claim 11, wherein the first group of resource elements or the second group of resource elements comprise three pairs of resource elements in one resource block, two resource elements in each of the three pairs are contiguous in a time domain, and two neighboring pairs of the three pairs are separated by at least four subcarriers in a frequency domain. ### Claim 13 (depends on 11) The communication apparatus according to claim 11, wherein the first group of resource elements or the second group of resource elements is grouped as shown in the Table below: Even-numbered slot Odd-numbered slot l = M l = M + 1 l = M l = M + 1 k = 11 G0 G0 G0 G0 k = 10 G1 G1 G1 G1 k = 6 G0 G0 G0 G0 k = 5 G1 G1 G1 G1 k = 1 G0 G0 G0 G0 k = 0 G1 G1 G1 G1 where k represents a subcarrier index in a resource block, l represents an Orthogonal Frequency Division Multiplexing (OFDM) symbol index, M represents an integer of 0 to 5, G0 represents the first group of resource elements, and G1 represents the second group of resource elements. ### Claim 14 (depends on 11) The communication apparatus according to claim 11, wherein each reference signal of the plurality of reference signals is multiplied by a corresponding orthogonal sequence in units of two or four neighboring resource elements with a same subcarrier index. ### Claim 15 (depends on 11) The communication apparatus according to claim 11, wherein the plurality of reference signals are used for demodulation of a physical downlink shared channel (PDSCH). ### Claim 16 A communication apparatus for receiving signals in a wireless communication system, the apparatus comprising: a radio frequency (RF) unit; and a processor operatively connected to the RF unit and configured to: receive a plurality of reference signals in one or more resource blocks on respective antenna ports of a first and second set of antenna ports, wherein each reference signal received on the first set of antenna ports is code division de-multiplexed from a first group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, wherein each reference signal received on the second set of antenna ports is code division de-multiplexed from a second group of resource elements in the one or more resource blocks by using a corresponding orthogonal sequence, and wherein the first set of antenna ports comprises antenna ports {N, N+1, N+4, N+6} and the second set of antenna ports comprises antenna ports {N+2, N+3, N+5, N+7}. ### Claim 17 (depends on 16) The communication apparatus according to claim 16, wherein the first group of resource elements or the second group of resource elements comprise three pairs of resource elements in one resource block, two resource elements in each of the three pairs are contiguous in a time domain, and two neighboring pairs of the three pairs are separated by at least four subcarriers in a frequency domain. ### Claim 18 (depends on 16) The communication apparatus according to claim 16, wherein the first group of resource elements or the second group of resource elements is grouped as shown in the Table below: Even-numbered slot Odd-numbered slot l = M l = M + 1 l = M l = M + 1 k = 11 G0 G0 G0 G0 k = 10 G1 G1 G1 G1 k = 6 G0 G0 G0 G0 k = 5 G1 G1 G1 G1 k = 1 G0 G0 G0 G0 k = 0 G1 G1 G1 G1 where k represents a subcarrier index in a resource block, l represents an Orthogonal Frequency Division Multiplexing (OFDM) symbol index, M represents an integer of 0 to 5, G0 represents the first group of resource elements, and G1 represents the second group of resource elements. ### Claim 19 (depends on 16) The communication apparatus according to claim 16, wherein each reference signal of the plurality of reference signals is multiplied by a corresponding orthogonal sequence in units of two or four neighboring resource elements with a same subcarrier index. ### Claim 20 (depends on 16) The communication apparatus according to claim 16, wherein the plurality of reference signals are used for demodulation of a physical downlink shared channel (PDSCH).