# US 10,485,031 B2 · Method, apparatus and system for processing very-high-speed random access > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,485,031 B2 - Document ID: US10485031B2 - Status: Granted - Kind: B2 - Application number: 16/026,830 - Filed: 2018-07-03 - Published: 2018-11-01 - Granted: 2019-11-19 - Earliest claimed: 2012-08-07 - Assignees: Huawei Technologies Co., Ltd. - Applicants: Huawei Technologies Co., Ltd. - Inventors: Li Wan - Web page: https://patentgrep.com/patent/US10485031B2 ## CPC - H04W 74/0833: Random access procedures, e.g. with 4-step access - H04J 13/0062: {Zadoff-Chu} - H04J 13/16: Code allocation - H04W 74/002: {Transmission of channel access control information} - H04W 74/006: {in the downlink, i.e. towards the terminal} - H04J 2011/0096: {Network synchronisation} - H04W 74/0838: using contention-free random access [CFRA] - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - 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) ## Abstract A method, an apparatus and a system process very-high-speed random access. The method includes: selecting a ZC sequence group according to a cell type and a first cyclic shift parameter Ncs, and setting N detection windows for each ZC sequence in the ZC sequence group, where N≥5; sending the cell type, a second Ncs, and the ZC sequence group to a UE; receiving a random access signal sent by the UE, and obtaining the random access sequence from the random access signal; performing correlation processing on the random access sequence with each ZC sequence in the ZC sequence group, detecting a valid peak value in the N detection windows of each ZC sequence, and determining an estimated value of an RTD according to the valid peak value, so that a UE in a very-high-speed scenario can normally access a network, thereby improving network access performance. ## Claims ### Claim 1 A method for processing very-high-speed random access, comprising: selecting, by a base station, a Zadoff-Chu (ZC) sequence group according to a cell type and a first cyclic shift parameter, wherein the ZC sequence group comprises M ZC sequences, and a duHT value of a jth ZC sequence in the ZC sequence group meets a condition  du HT  ∈ [ Ncs , Nzc - Ncs 4 ] ⋃ [ Nzc + Ncs 4 , Nzc - Ncs 3 ] ⋃ [ Nzc + Ncs 3 , Nzc - Ncs 2 ] , wherein Ncs is the first cyclic shift parameter, Nzc is the length of the jth ZC sequence, and j is an integer out of integers from 1 to M; and sending, by the base station, the cell type and the ZC sequence group to a user equipment (UE). ### Claim 2 (depends on 1) The method according to claim 1, wherein the method further comprises: setting N detection windows for each ZC sequence in the ZC sequence group, wherein N≥5. ### Claim 3 (depends on 2) The method according to claim 2, wherein the method further comprises: receiving a random access signal from the UE, and obtaining a random access sequence from the random access signal; and performing correlation processing on the random access sequence with each ZC sequence in the ZC sequence group, detecting a valid peak value in the N detection windows of each ZC sequence, and determining an estimated value of a round trip delay (RTD) according to the valid peak value. ### Claim 4 (depends on 3) The method according to claim 3, wherein setting the N detection windows for the jth ZC sequence in the ZC sequence group comprises: obtaining a duHT value of the jth ZC sequence in the ZC sequence group; determining start positions of the N detection windows of the jth ZC sequence according to the duHT value of the jth ZC sequence; and setting the N detection windows of the jth ZC sequence according to the start positions of the N detection windows of the jth ZC sequence and a preset detection window size; wherein the duHT value of the jth ZC sequence corresponds to a shift of a mirror image peak in a power delay profile (PDP) of the jth ZC sequence relative to the RTD when a frequency deviation is ± 1 T SEQ ⁢ , wherein TSEQ is a time duration occupied by the jth ZC sequence. ### Claim 5 (depends on 3) The method according to claim 3, wherein, when a frequency deviation range of very-high-speed random access is [ - 5 * Δ ⁢ ⁢ f RA 2 , 5 * Δ ⁢ ⁢ f RA 2 ] in which ΔfRA represents a subcarrier spacing of a random access channel, setting the N detection windows for the jth ZC sequence in the ZC sequence group comprises: obtaining a duHT value of the jth ZC sequence in the ZC sequence group; and setting five detection windows of the jth ZC sequence according to the duHT value of the jth ZC sequence; wherein the duHT value of the jth ZC sequence corresponds to a shift of a mirror image peak in a power delay profile (PDP) of the jth ZC sequence relative to the RTD when a frequency deviation is ± 1 T SEQ ⁢ , wherein TSEQ is a time duration occupied by the jth ZC sequence. ### Claim 6 (depends on 5) The method according to claim 5, wherein setting the five detection windows of the jth ZC sequence according to the duHT value of the jth ZC sequence comprises: obtaining start positions of the five detection windows of the jth ZC sequence according to the duHT value of the jth ZC sequence, wherein the five detection windows comprise a detection window {circle around (1)}, a detection window {circle around (2)}, a detection window {circle around (3)}, a detection window {circle around (4)} and a detection window {circle around (5)}, wherein a start position of the detection window {circle around (1)} is 0, wherein a start position of the detection window {circle around (2)} is mod(duHT, Nzc), wherein a start position of the detection window {circle around (3)} is mod(−duHT, Nzc), wherein a start position of the detection window {circle around (4)} is mod(2*duHT, Nzc), wherein a start position of the detection window {circle around (5)} is mod(−2*duHT, Nzc); and setting the five detection windows of the jth ZC sequence according to the start positions of the five detection windows and a preset detection window size. ### Claim 7 (depends on 3) The method according to claim 3, wherein detecting the valid peak value in the N detection windows of each ZC sequence and determining an estimated value of a round trip delay (RTD) according to the valid peak value comprises: detecting a primary peak value from valid peak values in the N detection windows of each ZC sequence; determining a search window for a secondary peak value in the valid peak values according to a detection window in which the primary peak value is located; detecting the secondary peak value in the search window for the secondary peak value, and determining an RTD estimation window according to a combination relation between the detection window in which the primary peak value is located and a detection window in which the secondary peak value is located; and determining the estimated value of the RTD according to a position of the valid peak value in the RTD estimation window. ### Claim 8 (depends on 3) The method according to claim 3, wherein determining the estimated value of the RTD according to the valid peak value comprises: determining an RTD estimation window according to a detection window in which the valid peak value is located; and determining the estimated value of the RTD according to a position of the valid peak value in the RTD estimation window. ### Claim 9 (depends on 3) The method according to claim 3, wherein the method further comprises: estimating a frequency deviation according to a detection window in which the valid peak value is located. ### Claim 10 (depends on 1) The method according to claim 1, wherein the method further comprises: when the duHT value of at least one ZC sequence in the ZC sequence group does not meet the condition, reselecting another ZC sequence group according to the cell type and the first cyclic shift parameter. ### Claim 11 An apparatus for processing very-high-speed random access, comprising: a processor; and a computer readable storage medium to store processor-executable instructions; wherein the processor-executable instructions, when executed by the processor, facilitate: selecting a Zadoff-Chu(ZC) sequence group according to a cell type and a first cyclic shift parameter, wherein the ZC sequence group comprises M ZC sequences, and a duHT value of a jth ZC sequence in the ZC sequence group meets a condition  du HT  ∈ [ Ncs , Nzc - Ncs 4 ] ⋃ [ Nzc + Ncs 4 , Nzc - Ncs 3 ] ⋃ [ Nzc + Ncs 3 , Nzc - Ncs 2 ] , wherein Ncs is the first cyclic shift parameter, Nzc is the length of the jth ZC sequence, and j is an integer out of integers from 1 to M; and sending the cell type and the ZC sequence group to a user equipment (UE). ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the processor-executable instructions, when executed by the processor, further facilitate: setting N detection windows for each ZC sequence in the ZC sequence group, wherein N≥5. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein the processor-executable instructions, when executed by the processor, further facilitate: receiving a random access signal sent by the UE and obtaining a random access sequence from the random access signal; and performing correlation processing on the random access sequence with each ZC sequence in the ZC sequence group, detecting a valid peak value in the N detection windows for each ZC sequence, and determining an estimated value of a round trip delay (RTD) according to the valid peak value. ### Claim 14 (depends on 13) The apparatus according to claim 13, wherein the processor-executable instructions, when executed by the processor, further facilitate: obtaining a duHT value of the jth ZC sequence in the ZC sequence group; determining start positions of the N detection windows of the jth ZC sequence according to the duHT value of the jth ZC sequence; and setting the N detection windows of the jth ZC sequence according to the start positions of the N detection windows of the jth ZC sequence and a preset detection window size; wherein the duHT value of the jth ZC sequence corresponds to a shift of a mirror image peak in a power delay profile (PDP) of the jth ZC sequence relative to the RTD when a frequency deviation is ± 1 T SEQ ⁢ , wherein TSEQ is a time duration occupied by the jth ZC sequence. ### Claim 15 (depends on 13) The apparatus according to claim 13, wherein, the processor-executable instructions, when executed by the processor, further facilitate: when a frequency deviation range of very-high-speed random access is [ - 5 * Δ ⁢ ⁢ f RA 2 , 5 * Δ ⁢ ⁢ f RA 2 ] , obtaining a duHT value of an jth ZC sequence in the ZC sequence group; and setting five detection windows of the jth ZC sequence according to the duHT value of the jthZC sequence; wherein the duHT value of the jth ZC sequence corresponds to a shift of a mirror image peak in a power delay profile (PDP) of the jth ZC sequence relative to the RTD when a frequency deviation is ± 1 T SEQ ⁢ , wherein TSEQ is a time duration occupied by the jth ZC sequence. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the processor-executable instructions, when executed by the processor, further facilitate: obtaining start positions of the five detection windows of the jth ZC sequence according to the duHT value of the jth ZC sequence, wherein the five detection windows comprise a detection window {circle around (1)}, a detection window {circle around (2)}, a detection window {circle around (3)}, a detection window {circle around (4)} and a detection window {circle around (5)}, wherein a start position of the detection window {circle around (1)} is 0, wherein a start position of the detection window {circle around (2)} is mod(duHT, Nzc), wherein a start position of the detection window {circle around (3)} is mod(−duHT, Nzc), wherein a start position of the detection window {circle around (4)} is mod(2*duHT, Nzc), and wherein a start position of the detection window {circle around (5)} is mod(−2*duHT, Nzc); and setting the five detection windows of the jth ZC sequence according to the start positions of the five detection windows and a preset detection window size. ### Claim 17 (depends on 11) The apparatus according to claim 11, wherein the processor-executable instructions, when executed by the processor, further facilitate: when the duHT value of at least one ZC sequence in the ZC sequence group does not meet the condition, reselecting another ZC sequence group according to the cell type and the first cyclic shift parameter. ### Claim 18 (depends on 13) The apparatus according to claim 13, wherein the processor-executable instructions, when executed by the processor, further facilitate: detecting a primary peak value from valid peak values in the N detection windows of each ZC sequence in the ZC sequence group; determining a search window for a secondary peak value in the valid peak values according to a detection window in which the primary peak value is located; detecting the secondary peak value in the search window for the secondary peak value, and determining an RTD estimation window according to a combination relation between the detection window in which the primary peak value is located and a detection window in which the secondary peak value is located; and determining the estimated value of the RTD according to a position of the valid peak value in the RTD estimation window. ### Claim 19 (depends on 13) The apparatus according to claim 13, wherein the processor-executable instructions, when executed by the processor, further facilitate: determining an RTD estimation window according to a detection window in which the valid peak value is located; and determining the estimated value of the RTD according to a position of the valid peak value in the RTD estimation window. ### Claim 20 (depends on 13) The apparatus according to claim 13, wherein the processor-executable instructions, when executed by the processor, further facilitate: estimating a frequency deviation according to a detection window in which the valid peak value is located.