公开(公告)号：JP2000299681A

公开(公告)日：2000-10-24

申请号：JP2000067096

申请日：2000-03-10

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  JUNII LEE ,  MICHAELA C BANDEABIIN

IPC: H04J11/00 ,  H04L5/02 ,  H04Q7/38 ,  H04J13/00

Abstract: PROBLEM TO BE SOLVED: To provide a cellular wireless system efficient in terms of spectrum. SOLUTION: This method uses offset between cells, especially, uses tone offset and time offset. When a first base station uses F1, F2,..., FN, a second base station adjacent to this first base station uses the tones of F1+Δf, F2+Δf,..., FN+Δf in the same frequency band. When the first base station starts continuous symbols at time T1, T2 and T3, the second base station adjacent to this first base station starts respective corresponding symbols at time T1+Δt, T2+Δt and T3+Δt. In the cellular system having the hexagonal cells, the tone sets of two adjacent cells are deviated just by 1/3 space between adjacent tones and the symbol timings of two adjacent cells are deviated just 1/3 symbol term.

公开(公告)号：JP2000299680A

公开(公告)日：2000-10-24

申请号：JP2000067095

申请日：2000-03-10

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  JUNII LEE ,  MICHAELA C BANDEABIIN

IPC: H04J11/00 ,  H04L5/02 ,  H04Q7/38 ,  H04J13/00

Abstract: PROBLEM TO BE SOLVED: To improve a method for a spread spectrum multiple access cellular radio system. SOLUTION: In the spread spectrum multiple access radio system of an orthogonal frequency division multiplex(OFDM) system, an entire band width is divided into orthogonal tones. On the side of transmission, a tone allocation unit 307 of an OFDM transmitter 301 allocates the extremely small number of orthogonal tones are allocated to the use of respective users to communicate audio information, and orthogonal tones more than the extremely small number are allocated to respective users to communicate the data information of a bit rate higher than that of audio information. Then, the allocated orthogonal tone is hopped within a usable spectrum with time by the tone allocation unit 307. Hopping of the allocated tone is performed at high speed on the downlink of the radio system but performed at low speed on the uplink and on the side of reception, similar tone allocation and tone hopping are performed as well.

公开(公告)号：JP2000286822A

公开(公告)日：2000-10-13

申请号：JP2000067097

申请日：2000-03-10

Applicant: LUCENT TECHNOLOGIES INC

Inventor： LAROIA RAJIV ,  JUNII LEE ,  MICHAELA C BANDEABIIN

IPC: H04J11/00 ,  H04J13/00 ,  H04L5/02 ,  H04Q7/36

Abstract: PROBLEM TO BE SOLVED: To provide a communication system where interference between cells is reduced by permitting a base station in the cell to use a directional antenna to adopt sectoring. SOLUTION: In order to adopt sectoring, a base station in a cell uses a directional antenna. Not only the cell is sectored from the viewpoint of transmission by the directivity of a down link antenna but also orthogonal frequency division multiplex(OFDM) tones adopted in the respective cells are correspondingly made to be orthogonal. Namely, the set of the tones is allocated in the sub- band of frequency band width, which can be used, so that it can be used at the time of transmitting it to the respective sectors in the cell. In a hexagonal cell 601, for example, the tones of the same sub-bands are allocated to all sectors 603, 605 and 607 having the same bearing. The sub-bands allocated to the sectors 603, 605 and 607 are periodically changed between the sub-bands that can be used in a band where the whole can be used.