| 摘要 |
The present invention relates to a random access method and a preamble structure for the same in an LTE-based mobile communication system to support a random access from a terminal which has a large cell area with a radius greater than 100 km and is power-limited. In the present invention, while the existing LTE random access preamble sequence is in use as-is, the reciprocation delay time difference among terminals in a large cell area can be compensated. Also, a greater link margin can be secured by transmitting higher power per bandwidth, and the compatibility with the existing LTE resource scheduling can be maintained. Furthermore, random accesses in a large cell are supported, and a preamble structure for a satellite mobile communication can be implemented based on the ground LTE. [Reference numerals] (AA) Start;(BB,D1,F1) Cell radius < R_TH1 ?;(CC) Proceed a random access process with the existing LTE manner;(D2,G1) Has enough link margin been secured ?;(D3,G2) Use a random access channel format 4;(D4) Select a transmission time section base station for random access (continuous 6 sub frame length);(D5,F4,G4,H3) Select a transmission frequency section base station for random access (countinuous 2 asset blocks);(D6,F5,G5,H4) Exclude a data scheduling process from a random access transmission asset section;(D7,F6,G6,H5) Command to transmit a random access channel to the random access transmission asset section;(D8,F7,G7,H6) Transmit the random access transmission asset section from a transmission section secured by BCH;(D9,F8) Detect a preamble through low-complexity frequency section processing in one window;(EE,D10,F9,G9,H8) End;(F2,H1) Use a random access channel format 5;(F3) Select a transmission time section base station for random access (continuous 9 sub frame length);(G3,H2) Select a transmission time section base station for random access (1 or 2 frame length);(G8,H7) Detect a preamble through high-complexity time section processing in multiple windows |
