Nippon Telegraph and Telephone Corporation

Nippon Electric Co., Ltd.

Nippon Telegraph and Telephone Public Corporation

Ntt Mobile Communications Network, Inc.

Masaharu Hata

Masayuki Sakamoto

Seizo Onoe

Fumiyuki Adachi

Akihiro Maebara

Kotaro Kato

Toshinori Fujii

A method of handover and route diversity in a mobile radio communication which is less time consuming and capable of improving the frequency spectrum utilization efficiency and securing the high quality of service regardless of the moving speed of the mobile station. In the method, a loop transmission line by which each base station is connected with neighboring base stations is provided; a handover information is transmitted through the loop transmission line, where the handover information is relayed by each base station from one of the neighboring base stations to another one of the neighboring base station; and the handover of a communication of a mobile station from one traffic channel of one base station to an idle traffic channel of another base station is carried out by using the handover information transmitted through the loop transmission line. The method can also be applied to a route diversity reception.

Method of handover and route diversity in mobile radio communication

Radio channel switching control method

A clock recovery circuit includes an oscillator having a frequency which is substantially equal to the clock frequency of bursts which are transmitted from a plurality of stations. A phase difference detector circuit responds to phase differences between clock signals extracted from each of the bursts and from the output from the oscillator. An averaging circuit averages the detected phase differences over an interval which is designated by a first control signal. A memory circuit stores the averaged phase difference in response to a second control signal and reads out the stored phase differences in response to a third control signal. A control circuit generates the first to third control signals in response to the output from the oscillator. A phase shift circuit shifts the phase of the output from the oscillator, based on the phase difference read out from the memory circuit. This generates and recovers the original clock pulse signal. The clock of the first burst corresponding to the stored phase difference is used as the clock for a second burst from the same station which transmits the first burst.

Clock recovery circuit for burst communications systems

Growing community of inventors

Yokosuka, Japan

Masaharu Hata