Receiving apparatus
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsIppei Kanno, Hiroaki Ozeki, Yasuo Oba, Akira Fujishima, Mineyuki Iwaida
Life of this patent
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Abstract
Frequency conversion into a first intermediate frequency which is higher than a received frequency band is performed for a received signal by using a mixer 63 and a PLL 64. Next, an output of the mixer 63 is frequency converted into a second intermediate frequency of base band by using a quadrature mixer formed by mixers 67, 68 and a phase shifter 70. At this time, a frequency of local oscillation signal of a PLL 69 supplied to the quadrature mixer is controlled so as to be switched, depending on a position of received segment, between a frequency which is higher than the first intermediate frequency and a frequency which is lower than the same.
Claims8
A receiving apparatus comprising:
- a first mixer which performs frequency conversion for a received signal obtained by connecting a plurality of segments and performing OFDM modulation for the segments into a first intermediate frequency which is set to be higher than a received frequency band;
- a second mixer for image rejection which performs frequency conversion for an output of said first mixer into a second intermediate frequency which is lower than said first intermediate frequency;
- and
- a control section which instructs so as to switch, depending on a position of segment, a frequency of a local oscillation signal to be supplied to said first mixer between a frequency which is higher than said first intermediate frequency and a frequency which is lower than said first intermediate frequency when a segment serving as a part of the received signal is selected and received.
A receiving apparatus comprising:
- a first mixer which performs frequency conversion for a received signal obtained by connecting a plurality of segments and performing OFDM modulation for the segments into a first intermediate frequency which is set to be higher than a received frequency band;
- a second mixer which performs quadrature detection for an output of said first mixer by using a local oscillation signal that a frequency offset is set;
- and
- a control section which instructs so as to switch a sign of said frequency offset depending on a position of said segment when a segment serving as a part of the received signal is selected and received.
A receiving apparatus comprising:
- a first mixer which performs frequency conversion for a received signal subjected digital modulation into a first intermediate frequency which is set to be higher than a received frequency band;
- a second mixer for image rejection which performs frequency conversion for an output of said first mixer into a second intermediate frequency which is lower than said first intermediate frequency;
- and
- a control section which instructs so as to switch, when a signal subjected to digital modulation is received under a circumstance that an adjacent signal exists, depending on a relative position of said adjacent signal and said received signal, a frequency of local oscillation signal to be supplied to said first mixer between a frequency which is higher than said first intermediate frequency and a frequency which is lower than said first intermediate frequency.
A receiving apparatus comprising:
- a first mixer which performs frequency conversion for a received signal subjected digital modulation into a first intermediate frequency which is set to be higher than a received frequency band;
- a second mixer which performs quadrature detection for an output of said first mixer by using a local oscillation signal that a frequency offset is set;
- and
- a control section which instructs so as to switch, when a signal subjected to digital modulation is received under a circumstance that an adjacent signal exists, a sign of said frequency offset depending on a relative position of said adjacent signal and said received signal.
Dependencies are inferred from the claim text.