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US 2009/0215422 A1Published application
Receiver
AssigneeNsc Co., Ltd.
InventorsTakeshi Ikeda, Hiroshi Miyagi
Life of this patent
Estimating the term…
Abstract
By providing switch portions (8a) and (8b) for switching I and Q signals and outputting them to a single A/D converter (9), and sequentially converting the I and Q signals output from the switch portions (8a) and (8b) into digital signals by the A/D converter (9) and supplying them to a DSP (10), it is possible to carry out an A/D conversion processing for the I and Q signals through the same A/D converter (9). Consequently, it is possible to eliminate a drawback that an amplitude error or a phase error is made between the I and Q signals due to a variation in an A/D converting characteristic.
Claims6
A receiver comprising:
- a polyphase filter for inputting a received radio frequency signal and outputting a four-phase radio frequency signal having phases shifted from each other by 90°;
- a mixer for frequency-converting the four-phase radio frequency signal output from the polyphase filter with a local oscillating signal having a local frequency and generating a four-phase intermediate frequency signal from the four-phase radio frequency signal;
- a switching portion for switching and outputting an in-phase signal having a positive phase and a quadrature signal having a positive phase which are contained in the intermediate frequency signals having positive phases among the four-phase intermediate frequency signals generated through the frequency-conversion in the mixer, and switching and outputting an in-phase signal having a negative phase and a quadrature signal having a negative phase which are contained in the intermediate frequency signals having negative phases among the four-phase intermediate frequency signals;
- an A/D converter for converting, into digital signals, the in-phase and quadrature signals which are sequentially switched and output by the switching portion;
- and
- a digital signal processing portion for carrying out a digital signal processing including a demodulation over the in-phase and quadrature signals output as the digital signals from the A/D converter,
- wherein the digital signal processing portion includes an amplitude correcting portion for correcting an amplitude for at least one of the in-phase and quadrature signals output as the digital signals from the A/D converter, and
- a phase correcting portion for correcting a phase for at least one of the in-phase and quadrature signals output as the digital signals from the A/D converter.
5 more elements
Dependencies are inferred from the claim text.