Radio signal receiving apparatus and demodulating circuit

• US 7,031,748 B2
• Filed: 07/09/2002
• Issued: 04/18/2006
• Est. Priority Date: 07/13/2001
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Takagi, Kotaro
• Primary Examiner(s): Urban, Edward
• Assistant Examiner(s): Haroon, Adeel
• Application Number:
  US10/363,793
• Publication Number:
  US 20030181174A1
• Time in Patent Office: 1,379 Days
• Field of Search: 455/552.1, 455/553.1, 455/209, 455/84, 455/86, 455/318, 455/319
• US Class Current: 455/553.1
• CPC Class Codes: H04B 1/005 adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes

Abstract

The object of this invention is to demodulate received signals having different received signal frequencies with the simple circuit configuration. With the present invention, the fixed frequency signals are generated at the fixed PLL unit 310, and simultaneously, the standard frequency signals corresponding respectively to GSM/DCS received RF signals are generated at the channel PLL unit 330. And using the image removal mixer 370 jointly to received RF signals, local oscillation signals having local oscillation frequencies equal to the received signal frequencies of the received RF signals respectively are formed from the fixed frequency signals and the standard frequency signals for receiving. And since the quadrature demodulators 254 and 264 demodulate the received RF signals using corresponding local oscillation signals respectively, the circuit configuration can be simplified by sharing the image removal mixer 370. Thereby, receiving signals having different received signal frequencies can be demodulated with the simple circuit configuration.

Claims

1. A wireless signal receiving device, comprising:

signal receiving means for receiving multiple received signals having different received signal frequencies;

fixed frequency signal generating means for generating fixed frequency signals having fixed frequencies;

standard frequency signal generating means for generating standard frequency signals for receiving having standard frequencies for receiving corresponding respectively to each of said received signals;

local oscillation signal generating means for generating local oscillation signals having local oscillation frequencies equal to said received signal frequencies of said received signals from said fixed frequency signals and said standard frequency signals for receiving and to be used in common in each of said received signals;

multiple demodulation means for demodulating said received signals by using said corresponding local oscillation signals;

specific demodulation means for demodulating the specific received signals having the prescribed frequency band wider than the frequency band that said received signals have out of each of said received signals; and

DC feedback means for applying DC feedback onto baseband signals to be obtained as a result of demodulation of said specific received signals from said specific demodulation means,

wherein said standard frequency signal generating means generates local oscillation frequency signals having local oscillation frequencies equal to received signal frequencies of said specific received signals by changing optional standard frequencies for receiving out of each of said standard frequencies for receiving; and

said specific demodulation means demodulates said specific received signals by using said local oscillation signals generated by said standard frequency signal generating means.

2. A wireless signal receiving device according to claim 1, comprising:

transmission signal generating means for generating multiple transmission signals having different transmission signal frequencies by applying a transmission processing to prescribed signals; and

transmission means for transmitting each of said transmission signals, wherein;

said standard frequency signal generating means generates standard frequency signals for transmission having standard frequencies for transmission corresponding respectively to each of said transmission signals by changing each of said standard frequencies for receiving; and

said transmission signal generating means generates each of said transmission signals by applying a transmission processing to said signals by using said fixed frequency signals and said standard frequency signals for transmission.

3. A demodulation processing circuit, comprising:

fixed frequency signal generating means for generating fixed frequency signals having fixed frequencies;

standard frequency signal generating means for generating standard frequency signals for receiving having standard frequencies for receiving corresponding respectively to multiple received signals having different received signal frequencies;

local oscillation signal generating means for generating local oscillation signals having local oscillation frequencies equal to said received signal frequencies of said received signals from said fixed frequency signals and said standard frequency signals for receiving and to be used in common-in each of said received signals;

multiple demodulation means for demodulating said received signals by using said corresponding local oscillation signals;

specific demodulation means for demodulating specific received signals having the prescribed frequency band wider than the frequency band that said received signals have in said received signals; and

DC feedback means for applying DC feedback onto baseband signal to be obtained as a result of demodulation of said specific received signals from said specific demodulation means, wherein;

said standard frequency signal generating means generates local oscillation signals having local oscillation frequencies equal to received signal frequencies of said specific received signals by changing optional standard frequencies for receiving out of said standard frequencies for receiving; and

said specific demodulation means demodulates said specific received signals by using said local oscillation signals generated by said standard frequency signal generating means.

4. A demodulation processing circuit according to claim 3, wherein:

said fixed frequency signal generating means generates said fixed frequency signals having said fixed frequencies to be used commonly in generating multiple transmission signals having different transmission signal frequencies; and

said standard frequency signal generating means generates standard frequency signals for transmission having standard frequencies for transmission to be used for generating said transmission signals corresponding to each of said transmission signals by changing said standard frequencies for receiving.