Signal selector

DETAILED DESCRIPTION In accordance with one aspect of the present invention, there is provided a DBS receiving system which overcomes the aforedescribed inability of two-output voltage IRDs to select satellite signals having a given characteristic (e.
g.
satellite location, downlink frequency, and/or polarization state) from a set which may, in some embodiments, include more than two alternatives.
The receiving system is useful in communication systems capable of delivering signals having a plurality of different characteristics and includes one or more selectors responsive to a state selection signal having a number of states at least equal to the number of alternative signal characteristics.
The selector(s) includes a command decoder for decoding the state selection signal, and apparatus (e.
g.
switching apparatus) responsive to the command decoder output for selecting a particular one of the signal characteristics corresponding to the particular state of the state selection signal.
The state selection signal may take a variety of forms.
In accordance with one aspect of the invention, the state selection signal may be a pattern of pulses or other state transitions whose count is indicative of a particular selected signal characteristic.
For example, the transmission of a single pulse might indicate selection of a LHCP signal from a first satellite, whereas transmission of three pulses might indicate selection of a RHCP signal from a second satellite.
The pulses may preferably comprise two quasi-constant voltage levels corresponding to the two-output DC voltage levels available in known IRDs for selecting LNB polarization states.
The invention itself, together with further objects and attendant advantages, will best be understood by reference to the following description of presently preferred embodiments, taken in conjunction with the accompanying drawings.