CDMA cellular hand-off apparatus and method
US5345467A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 8, 1992 |
| Grant date | Sep 6, 1994 |
| Priority date | — |
| Expiry date | Oct 8, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W36/302
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An apparatus for controlling hand-off in a spread-spectrum-CDMA-communications system, for radio devices moving from one cell to another, with each cell having a base station transmitting spread spectrum signals with generic-chip-code signals. A radio device includes a cellular antenna, matched filters, and detectors for detecting generic-chip-code signals embedded in spread-spectrum-communications signals. A comparator generates a comparison signal by comparing the relative time of arrival of a second detected signal with a first detected signal. A receiver-message-chip-code generator generates a replica of the message-chip-code signal, and a message mixer despreads the spread-spectrum-communications signal. A synchronization circuit synchronizes the receiver-message-chip-code generator to the first generic-chip-code signal for receiving the first spread-spectrum-communications signal or to the second generic-chip-code signal for receiving the second spread-spectrum communications signal, depending on a threshold. A control unit switches transmitting the message data, embedded in the first spread-spectrum-communications signal from the first base station, to the second spread-spec…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.