# US 8,543,151 B2 · Method for generating downlink frame, and method for searching cell > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,543,151 B2 - Document ID: US8543151B2 - Status: Granted - Kind: B2 - Application number: 13/572,076 - Filed: 2012-08-10 - Published: 2012-12-13 - Granted: 2013-09-24 - Earliest claimed: 2007-07-19 - Assignees: Samsung Electronics Co., Ltd.; Electronics and Telecommunications Research Institute - Applicants: Il Gyu Kim; Young Jo Ko; Hyeong Geun Park; Kap Seok Chang; Hyo Seok Yi; Young-Hoon Kim; Seung Chan Bang; Kyoung Joon Lee - Inventors: Il Gyu Kim; Young Jo Ko; Hyeong Geun Park; Kap Seok Chang; Hyo Seok Yi; Young-Hoon Kim; Seung Chan Bang; Kyoung Joon Lee - Web page: https://patentgrep.com/patent/US8543151B2 ## CPC - H04L 27/261: {Details of reference signals} - H04J 11/0076: {Acquisition of secondary synchronisation channel, e.g. detection of cell-ID group} - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04W 48/16: Discovering, processing access restriction or access information - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - 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) - 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 method of generating a downlink frame. The method of generating the downlink frame includes generating a first sequence and a second sequence for identifying cell groups; generating a first scrambling sequence and a second scrambling sequence that are one-to-two mapped to the sequence number of the primary synchronization signal; scrambling the first sequence with the first scrambling sequence and scrambling the second sequence with the second scrambling sequence; and generating a secondary synchronization signal including the scrambled first sequence and second sequence and mapping the secondary synchronization signal to a frequency domain. ## Claims ### Claim 1 A method for generating a frame in a cellular system, the method comprising: generating a first sequence and a second sequence for identifying cell groups; generating a first scrambling sequence and a second scrambling sequence that are mapped to a sequence number of a primary synchronization signal; scrambling the first sequence with the first scrambling sequence and scrambling the second sequence with the second scrambling sequence; and mapping the scrambled first sequence and the scrambled second sequence to a frequency domain. ### Claim 2 (depends on 1) The method of claim 1, wherein mapping scrambled first sequence and the scrambled second sequence includes alternately disposing the scrambled first sequence and the scrambled second sequence on a plurality of sub-carriers of the frequency domain. ### Claim 3 (depends on 1) The method of claim 1, wherein scrambling the first sequence includes multiplying each element of the first sequence by each element of the first scrambling sequence corresponding to each element of the first sequence, and scrambling the second sequence includes multiplying each element of the second sequence by each element of the second scrambling sequence corresponding to each element of the second sequence. ### Claim 4 (depends on 1) The method of claim 1, wherein the first sequence and the second sequence are cyclic shifted sequences of an m-sequence, respectively. ### Claim 5 (depends on 1) The method of claim 1, wherein the first scrambling sequence is an m-sequence that has different primitive polynomial from the first sequence or a cyclic shifted sequence of the m-sequence. ### Claim 6 An apparatus for generating a frame, comprising: a sequence generator that generates a first sequence and a second sequence for identifying cell groups and generates a first scrambling sequence and a second scrambling sequence that are mapped to a sequence number of a primary synchronization signal; and a synchronization signal generator that scrambles the first sequence with the first scrambling sequence, scrambles the second sequence with the second scrambling sequence, and maps the scrambled first sequence and the scrambled second sequence to a frequency domain. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the synchronization signal generator maps the scrambled first sequence and the scrambled second sequence to the frequency domain by alternately disposing the scrambled first sequence and the scrambled second sequence on a plurality of sub-carriers of the frequency domain. ### Claim 8 (depends on 6) The apparatus of claim 6, wherein each element of the first sequence is multiplied by each element of the first scrambling sequence corresponding to each element of the first sequence, and each element of the second sequence is multiplied by each element of the second scrambling sequence corresponding to each element of the second sequence. ### Claim 9 (depends on 6) The apparatus of claim 6, wherein the first sequence and the second sequence are a cyclic shift sequence of an m-sequence, respectively. ### Claim 10 (depends on 6) The apparatus of claim 6, wherein the first scrambling sequence is an m-sequence that has different primitive polynomial from the first sequence or a cyclic shifted sequence of the m-sequence. ### Claim 11 A method for searching a cell in a terminal, comprising: receiving a downlink frame including a primary synchronization signal and a secondary synchronization signal; and determining a cell group to which a terminal belongs, by using the secondary synchronization signal, wherein in the secondary synchronization signal, a first sequence scrambled with a first scrambling sequence and a second sequence scrambled with a second scrambling sequence are mapped to a frequency domain, and the first scrambling sequence and the second scrambling sequence are mapped to a sequence number of the primary synchronization signal. ### Claim 12 (depends on 11) The method of claim 11, wherein the scrambled first sequence and the scrambled second sequence are alternately disposed on a plurality of sub-carriers of the frequency domain. ### Claim 13 (depends on 11) The method of claim 11, further comprising identifying a cell to which the terminal belonged, by using the primary synchronization signal. ### Claim 14 (depends on 11) The method of claim 11, wherein the first sequence and the second sequence are a cyclic shifted sequence of an m-sequence, respectively. ### Claim 15 (depends on 11) The method of claim 11, wherein the first scrambling sequence is an m-sequence that has different primitive polynomial from the first sequence or a cyclic shifted sequence of the m-sequence. ### Claim 16 An apparatus for searching a cell, comprising: a receiving antenna that receives a downlink frame including a primary synchronization signal and a secondary synchronization signal; and a cell searcher that identifies a cell group to which the terminal belongs, from the secondary synchronization signal, wherein in the secondary synchronization signal, a first sequence scrambled with a first scrambling sequence and a second sequence scrambled with a second scrambling sequence are mapped to a frequency domain, and the first scrambling sequence and the second scrambling sequence are mapped to a sequence number of the primary synchronization signal. ### Claim 17 (depends on 16) The apparatus of claim 16, wherein the scrambled first sequence and the scrambled second sequence are alternately disposed on a plurality of sub-carriers of the frequency domain. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein the cell searcher identifies a cell to which the terminal belonged, by using the primary synchronization signal. ### Claim 19 (depends on 16) The apparatus of claim 16, wherein the first sequence and the second sequence are a cyclic shift sequence of an m-sequence, respectively. ### Claim 20 (depends on 16) The apparatus of claim 16, wherein the first scrambling sequence is an m-sequence that has different primitive polynomial from the first sequence or a cyclic shifted sequence of the m-sequence.