TDMA mobile phone for antenna switching diversity system with booster

摘要

PROBLEM TO BE SOLVED: To reduce the number of coaxial cables for connection between a TDMA portable telephone set and a booster to one and to reduce the current consumption of the portable telephone set. SOLUTION: When a booster 4 on a vehicle and a portable telephone set 1 are connected, a transmission TDMA signal S1 from a transmission circuit 11 is amplified by a transmission amplifier 45, and an amplified transmission TDMA signal S6 is transmitted from an antenna 52 of a system 1. Meanwhile, a reception TDMA signal S8a which passes the antenna 52 of the system 1 and a reception amplification part 46 of the system 1 is supplied to the first selection terminal of a switch 43, and a reception TDMA signal S8b from an antenna 63 of a system 2 and a reception amplification part 48 of the system 2 is supplied to the second selection terminal of the switch 43. A control circuit 18 receives the reception level comparison result of the reception TDMA signal measured in the level measuring slot of a radio channel by a reception circuit 13 and supplies one of signals S8a and S8b, which has a higher level, from the switch 43 to the portable telephone set 1 by a coaxial cable 2.