초록 ▼

A radio communications system provides frequency channels which are formed both by time slots and by broadband frequency ranges, and in which information from a plurality of connections is simultaneously transmitted between mobile stations and base stations wherein it is possible to distinguish the

A radio communications system provides frequency channels which are formed both by time slots and by broadband frequency ranges, and in which information from a plurality of connections is simultaneously transmitted between mobile stations and base stations wherein it is possible to distinguish the information from different connections in accordance with a connection-specific fine structure. Frequency channels are repeatedly provided for time synchronization of the mobile stations in the downward direction in which a signal form is transmitted in addition to information from further connections. The mobile station to be synchronized determines from received signals at least one instant of the arrival of the signal form, which is subsequently used by the mobile station for time synchronization. The system is advantageously applied, for example, in TDD mode for the third mobile communications generation which combines a TDMA and CDMA subscriber separation method.

대표청구항 ▼

A radio communications system provides frequency channels which are formed both by time slots and by broadband frequency ranges, and in which information from a plurality of connections is simultaneously transmitted between mobile stations and base stations wherein it is possible to distinguish the

A radio communications system provides frequency channels which are formed both by time slots and by broadband frequency ranges, and in which information from a plurality of connections is simultaneously transmitted between mobile stations and base stations wherein it is possible to distinguish the information from different connections in accordance with a connection-specific fine structure. Frequency channels are repeatedly provided for time synchronization of the mobile stations in the downward direction in which a signal form is transmitted in addition to information from further connections. The mobile station to be synchronized determines from received signals at least one instant of the arrival of the signal form, which is subsequently used by the mobile station for time synchronization. The system is advantageously applied, for example, in TDD mode for the third mobile communications generation which combines a TDMA and CDMA subscriber separation method. lar shape or at regular intervals along one circumference; and said groove is arranged below an upper end of said main shaft of said motor unit, thereby thrusting said centering member toward said turntable unit side by an attractive force of said magnet, and engaging an outer periphery of said centering member with an outside periphery of said groove, to carry out centering. 5. The disk retaining mechanism according to claim 2, wherein: said ferromagnetic body is disposed within said disk depressing member to constitute a clamper yoke; said clamper yoke is vertically slidable with respect to said disk depressing member, and it is disposed concentrically to said depressing member; said magnet is disposed annularly on said turntable unit; said groove is formed in an annular shape or at regular intervals along one circumference; and a resilient member having a resilient force is disposed between said clamper yoke and said disk depressing member, the resilient force being generally smaller than an attractive force of magnetism between said magnet on said turntable unit and said clamper yoke. 6. A disk retaining mechanism according to claim 1 wherein: said clamper unit comprises a disk depressing member for depressing a disk and a centering member projecting downwardly from said disk depressing member and disposed at about the center of said disk depressing member; said turntable unit has a hole for engaging with said centering member; and said motor unit has a main shaft engaged with said turntable unit: wherein a magnet is disposed on one of said disk depressing member and said turntable unit, and a ferromagnetic body is disposed on the other one in a position confronting said magnet, thereby attracting said disk depressing member to said turntable unit by an attractive force of said magnet. 7. The disk retaining mechanism according to claim 6, wherein: said magnet is disposed within said disk depressing member; said ferromagnetic body is disposed on said turntable unit; said hole is formed at regular intervals along one circumference; and said hole is arranged below an upper end of said main shaft, thereby thrusting said centering member toward said turntable unit side by an attractive force of said magnet, and engaging an outer periphery of said centering member with an outer periphery of said hole, to carry out centering. 8. The disk retaining mechanism according to claim 6, wherein: said ferro