Diversity receiving apparatus for a mobile unit
US5777693A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1996 |
| Grant date | Jul 7, 1998 |
| Priority date | — |
| Expiry date | Aug 1, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/44209
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a first diversity receiving apparatus, during an antenna selection operation, one of antennas are selected such that each of antennas successively connected to a receiver for consecutive horizontal retrace periods but for horizontal scanning periods following the horizontal retrace period, the selected antenna showing a largest level at the previous antenna selection operation is connected to the receiver to detect levels derived from respective antennas. The antenna showing a largest level is selected at the current antenna selection operation to receive a radio wave television signal for the following M (a natural number) horizontal scanning cycles. M is changed in accordance with the phasing condition. For example, M is changed according to a speed of vehicle, a field intensity, a frequency of the received television signal, etc. The switching circuit and tuner may be provided doubly to prevent the affection of switching noise. A second apparatus determines the selected antenna by further detecting noise levels derived from the respective antennas during a vertical retrace period. A frequency of switching of antennas for determining the selected antenna is reduced to reduce a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.