Cable communication apparatus and cable communication method
AssigneeKabushiki Kaisha Toshiba
InventorsKatsuya Kudo, Masami Oosawa
Life of this patent
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Abstract
A STB 1 of this CATV system includes a diplexer 11, a signal level adjusting unit 30, a splitter 12, a tuner 2, a demodulating unit 3, a memory 17, and a CPU 19. The CPU 19 finds a correct reception level of a downstream signal by arithmetically operating a level correction value which is found based on a detected level adjustment state (state of switches) of the signal level adjusting unit 30 and a reception level after AGC which is found from signal intensity outputted from the demodulating unit 3, and notifies the found reception level to a CATV center station 40 by means of an upstream signal.
Claims13
A cable communication apparatus, comprising:
- a branching filter branching a downstream first RF signal sent from a CATV network and an upstream second RF signal which is in a frequency band different from a frequency band of the first RF signal, according to the frequency bands;
- a gain adjusting unit adjusting a gain of the first RF signal received through the branching filter, upon receiving a control or an operation;
- a splitter distributing the first RF signal gain-adjusted by the gain adjusting unit to a plurality of lines;
- a receiving unit having an auto gain control circuit controlling a gain of the first RF signal of at least one line out of the plural lines to which the first RF signal is distributed by the splitter, and obtaining a data processing reception signal from the signal gain-controlled by the auto gain control circuit;
- a memory storing gain adjustment states of the gain adjusting unit and level correction values of the first RF signal in correspondence to each other;
- and
- a reception level notifying unit calculating a reception level of the reception signal by using the level correction value of the first RF signal, which is read from the memory according to the gain adjustment state of the gain adjusting unit, and information indicating a reception state of the reception signal, and transmitting the calculated reception level on the CATV network through the branching filter by the second RF signal.
A cable communication method, comprising:
- branching a downstream first RF signal sent from a CATV network;
- adjusting, by a gain adjusting unit, a gain of the first RF signal upon receiving a control or an operation;
- distributing the gain-adjusted first RF signal to a plurality of lines;
- obtaining a data processing reception signal from a signal resulting from auto gain control of the first RF signal of at least one line out of the plural lines to which the first RF signal is distributed;
- storing, in a memory, gain adjustment states of the gain adjusting unit and level correction values of the first RF signal in advance in correspondence to each other;
- calculating a reception level of the reception signal by using the level correction value of the first RF signal, which is read from the memory according to the gain adjustment state of the gain adjusting unit, and information indicating a reception state of the reception signal;
- and
- transmitting the calculated reception level of the reception signal on the CATV network by an upstream second RF signal which is in a frequency band different from a frequency band of the first RF signal.
Dependencies are inferred from the claim text.