Sanyo Electric Co., Ltd.

Sanyo Telecommunications Co., Ltd.

Yasunori Akatsuka

Masahiro Narita

Yoshiharu Doi

Toshinori Iinuma

Hiroyasu Yoshida

Yasukazu Kamei

Daiki Takiguchi

The present invention aims to provide a radio base station that has equivalently high reception sensitivity without increasing the number of antenna elements while keeping the utilization efficiency of time slots high. The radio base station comprises a radio unitand a radio unitTwo time slots, one at each radio unit, are allocated to a mobile station. After a signal transmitted from the mobile station is received and demodulated, a piece of data received by the radio unitis compared with a piece of data received by the radio unitso that one of the pieces of data that has fewer errors is selected.

Diversity receiving radio base station with high reception sensitivity and high time slot utilization efficiency

An RF circuit () satisfies Pnoise+NF+G&#x2266;Plim+sW (0&#x2266;s&#x2266;4) at an edge of a guard band with respect to a required transmission level PAll, an upper tolerance level of out-of-band noise Plim, a guard bandwidth W, and a noise level Pnoise, where NF is a noise figure and G is a gain. An IF circuit () satisfies PAll&#x2266;Pin+G, where PIF is an output level of a BPF (). Out-of-band noise levels are reduced to Pnoise by the steep BPF (). The RF circuit () is structured so that noise from a local oscillator circuit () does not surpass noise from the IF circuit (). Reductions in power consumption are thus realized in addition to guard bandwidth reductions, because of being able to eliminate out-of-band noise from an amplifier () using a low-loss filter () having an attenuation slope s.

Signal generation device

A radio apparatus includes an antenna (), and a transmission circuit () and a receiving circuit () sharing the antenna. The apparatus connects an output of the transmission circuit to an input of the receiving circuit in calibration for calculating the quantity of phase rotation and/or the quantity of amplitude fluctuation of a signal passing through the transmission and receiving circuits. Then, it connects a reference signal to the input of the receiving circuit for calculating the quantity of phase rotation and/or the quantity of amplitude fluctuation of a signal passing through the receiving circuit. Based on the subtraction of the information, the quantity of phase rotation and/or the quantity of amplitude fluctuation of a signal passing through the transmission circuit is calculated. It calculates a correction value for correcting difference in quantity of phase rotation and/or quantity of amplitude fluctuation between the transmission and receiving circuits on the basis of the information. Thus, the difference in quantity of phase rotation and/or quantity of amplitude fluctuation between the transmission circuit and the receiving circuit can be corrected.

Radio device and method of calibration of antenna directivity

The present invention is aimed at providing a base station for mobile communication systems which is capable of communicating with more mobile station than in the prior art while keeping high communication quality and restraining a rise in production cost. The base station of the present invention is used in mobile communication systems in which diversity is conducted. Such a base station includes an RF unit for generating a plurality of high-frequency transmission signals, an antenna selecting unit for switching connection of the transmission signal output of the RF unit from one antenna to another, a cross switch for switching the data transmission route between straight connection and cross connection by inputting transmission data from TDMA processing units and interchangeably to transmitting units and of the RF unit, and a control unit for controlling the antenna selecting unit so that the transmission signals will be connected to different antennas, respectively.

Growing community of inventors

Hashima, Japan

Yasunori Akatsuka