Radio communication system and radio-frequency integrated circuit
First Claim
1. A radio communication system comprising:
- a plurality of antennas;
a reception-system circuit including variable gain amplification circuits for amplifying a signal received by either of said plurality of antennas and a frequency conversion circuit for down-converting the received signal to a signal of a lower frequency;
a signal measuring circuit for detecting intensity of the received signal; and
a control circuit for determining change rates with time of a signal which is formed by said signal measuring circuit in respect of each of the signals received by said plurality of antennas and generating a signal for selecting a reception antenna in accordance with a difference between the change rates of the signals received by said plurality of antennas.
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Accused Products
Abstract
In a radio communication system having a plurality of antennas, a reception-system circuit including variable gain amplification circuits for amplifying a signal received from either of the antennas and a frequency conversion circuit for down-converting the received signal to a signal of a lower frequency, and a signal measuring circuit for detecting intensity of the received signal, whereby a signal received by either of the antennas is selected in accordance with a reception state and amplified and demodulated, change rates with time of a signal which is formed by the signal measuring circuit are determined in respect of either of the signals received by the plurality of antennas and a control signal for selecting a reception antenna is generated in accordance with a differences between the change rates.
19 Citations
18 Claims
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1. A radio communication system comprising:
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a plurality of antennas;
a reception-system circuit including variable gain amplification circuits for amplifying a signal received by either of said plurality of antennas and a frequency conversion circuit for down-converting the received signal to a signal of a lower frequency;
a signal measuring circuit for detecting intensity of the received signal; and
a control circuit for determining change rates with time of a signal which is formed by said signal measuring circuit in respect of each of the signals received by said plurality of antennas and generating a signal for selecting a reception antenna in accordance with a difference between the change rates of the signals received by said plurality of antennas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A radio-frequency IC comprising:
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a reception-system circuit including variable gain amplification circuits for amplifying a signal received by either of plural antennas and a frequency conversion circuit for down-converting the received signal to a signal of a lower frequency;
a signal measuring circuit for detecting intensity of the received signal; and
a control circuit for determining change rates with time of a signal which is formed by said signal measuring circuit in respect of either of the signals received by said plural antennas and generating a signal for selection of a reception antenna in accordance with a difference between the change rates. - View Dependent Claims (14, 15, 16, 17, 18)
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Specification