# US 10,374,857 B2 · Transmitting and receiving reference signals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,374,857 B2 - Document ID: US10374857B2 - Status: Granted - Kind: B2 - Application number: 14/889,779 - Filed: 2015-10-30 - Published: 2017-09-07 - Granted: 2019-08-06 - Earliest claimed: 2015-10-30 - Assignees: Telefonaktiebolaget L M Ericsson (publ) - Applicants: Telefonaktiebolaget L M Ericsson (Publ) - Inventors: Henrik Sahlin; Jianfeng Wang; Icaro L. J. da Silva - Web page: https://patentgrep.com/patent/US10374857B2 ## CPC - H04L 27/2613: {Structure of the reference signals} - 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 27/2607: {Cyclic extensions} - H04L 27/26132: {using repetition} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract There is provided mechanisms for transmitting reference signals. A method is performed by a first network device. The method comprises transmitting, in a single orthogonal frequency-division multiplexing (OFDM) symbol, a composite reference signal to a second network device. The composite reference signal is a time domain concatenation of at least a first reference signal and a last reference signal. The composite reference signal has a single cyclic prefix. The cyclic prefix is determined according to a last part of the single OFDM symbol. There is also provided mechanisms for receiving such reference signals. ## Claims ### Claim 1 A method for transmitting reference signals, the method being performed by a first network device, comprising: transmitting, in a single orthogonal frequency-division multiplexing, OFDM, symbol, a composite reference signal to a second network device, wherein the composite reference signal is a time domain concatenation of at least a first reference signal and a last reference signal wherein the first reference signal and the last reference signal are different and convey different information, wherein the composite reference signal has a single cyclic prefix, and wherein the cyclic prefix is determined according to a last part of the single OFDM symbol. ### Claim 2 (depends on 1) The method according to claim 1, wherein the composite reference signal is transmitted in a first transmission beam at a first time instant, the method further comprising: transmitting at least one further instance of the composite reference signal, each at least one further instance of the composite reference signal being transmitted in a respective transmission beam at a respective second time instant, wherein each transmission beam is transmitted in a unique direction. ### Claim 3 (depends on 1) The method according to claim 1, wherein one instance of the composite reference signal is transmitted on a plurality of sub-carriers, each sub-carrier having its own carrier frequency. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: repeatedly and periodically transmitting the composite reference signal in a first transmission beam. ### Claim 5 (depends on 4) The method according to claim 4, wherein the composite reference signal is repeatedly and periodically transmitted in the first transmission beam in N4 consecutive OFDM symbols, where N4>1 is an integer. ### Claim 6 (depends on 4) The method according to claim 4, wherein the composite reference signal is repeatedly and periodically transmitted in the first transmission beam every N5 OFDM symbol intervals, where N5>1 is an integer. ### Claim 7 A method for receiving reference signals, the method being performed by a second network device, comprising: receiving, in a single orthogonal frequency-division multiplexing, OFDM, symbol, a composite reference signal from a first network device, wherein the composite reference signal is a time domain concatenation of at least a first reference signal and a last reference signal, wherein the first reference signal and the second reference signal are different and convey different information, wherein the composite reference signal has a single cyclic prefix, and wherein the cyclic prefix is determined according to a last part of the single OFDM symbol. ### Claim 8 (depends on 7) The method according to claim 7, wherein the composite reference signal is received in a first transmission beam at a first time instant, the method further comprising: receiving at least one further instance of the composite reference signal, each at least one further instance of the composite reference signal being received in a respective transmission beam at a respective second time instant, wherein each transmission beam is received in a unique direction. ### Claim 9 (depends on 7) The method according to claim 7, wherein the first reference signal in the single OFDM symbol is detected prior to the second reference signal in the same single OFDM symbol, and wherein at least one of power and frequency offset of the received singe OFDM symbol is estimated from the first reference signal and the second reference signal. ### Claim 10 (depends on 7) The method according to claim 7, wherein one instance of the composite reference signal is received on at least one of a plurality of sub-carriers, each sub-carrier having its own carrier frequency. ### Claim 11 (depends on 7) The method according to claim 7, further comprising: repeatedly and periodically receiving the composite reference signal in a first transmission beam. ### Claim 12 (depends on 11) The method according to claim 11, wherein the composite reference signal is repeatedly and periodically received in the first transmission beam in N4 consecutive OFDM symbols, where N4>1 is an integer. ### Claim 13 (depends on 11) The method according to claim 11, wherein the composite reference signal is repeatedly and periodically received in the first transmission beam every N5 OFDM symbol intervals, where N5>1 is an integer. ### Claim 14 (depends on 7) The method according to claim 7, wherein the composite reference signal is a time domain concatenation of the first reference signal, at least one intermediate reference signal, and the last reference signal. ### Claim 15 (depends on 7) The method according to claim 7, wherein the first reference signal is a time synchronization signal, TSS, and wherein the last reference signal is a mobility reference signal, MRS. ### Claim 16 (depends on 7) The method according to claim 7, wherein the first reference signal and the last reference signal provide hierarchical representations of an identity of the first network device or of a first transmission beam used for transmission of the composite reference signal. ### Claim 17 (depends on 7) The method according to claim 7, wherein the first reference signal and the last reference signal provide hierarchical representations of a timing indication. ### Claim 18 (depends on 7) The method according to claim 7, wherein each at least one intermediate reference signal is a mobility reference signal, MRS. ### Claim 19 (depends on 7) The method according to claim 7, wherein the OFDM symbol is a discrete Fourier transform, DFT, precoded OFDM symbol. ### Claim 20 (depends on 7) The method according to claim 7, wherein at least the first reference signal comprises a Zadoff-Chu sequence.