Multi-mode radio transceiver

• US 4,731,796 A
• Filed: 06/19/1987
• Issued: 03/15/1988
• Est. Priority Date: 10/25/1984
• Status: Expired due to Fees

• Current Assignee: UNM Rainforest Innovations (f/k/a STC.UNM) (The University of New Mexico)
• Original Assignee: UNM Rainforest Innovations (f/k/a STC.UNM) (The University of New Mexico)
• Inventors: Ramsdale, Peter A., Masterton, John
• Primary Examiner(s): Safourek, Benedict V.
• Assistant Examiner(s): Telesz, Jr., Andrew J.
• Application Number:
  US07/064,240
• Time in Patent Office: 270 Days
• Field of Search: 375/39, 375/42, 375/46, 375/75, 375/76, 375/77, 375/79, 375/118, 375/119, 375/9, 375/43, 329/131, 329/132, 329/133, 329/135, 455/304, 455/305, 455/73, 455/93, 455/142, 455/84, 307/511, 307/512, 328/168, 370/11
• US Class Current: 375/223
• CPC Class Codes: H03C 5/00 Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal H03C7/00 takes precedence
• CPC Class Codes: H03D 1/2245 using two quadrature channels H03D1/2209 takes precedence
• CPC Class Codes: H03D 2200/0025 Gain control circuits
• CPC Class Codes: H03D 2200/0029 Loop circuits with controlled phase shift
• CPC Class Codes: H03D 2200/0047 Offset of DC voltage or frequency
• CPC Class Codes: H03D 2200/005 Analog to digital conversion
• CPC Class Codes: H03D 2200/0052 Digital to analog conversion
• CPC Class Codes: H03D 3/008 Compensating DC offsets
• CPC Class Codes: H03D 3/009 Compensating quadrature phase or amplitude imbalances
• CPC Class Codes: H03D 5/00 Circuits for demodulating amplitude-modulated or angle-modulated oscillations at will H03D9/00, H03D11/00 take precedence
• CPC Class Codes: H04B 1/406 with more than one transmission mode, e.g. analog and digital modes

Abstract

A multi-mode radio transceiver comprising a sequence of bi-directional circuit modules including a radio frequency input/output amplifier module (1), a radio frequency/baseband I and Q quadrature channel conversion module (2), an analogue/digital conversion module (3), a digital signal processor (4,5), and a digital signal input/output interface (6), with a control means (7) whereby for transmission a radio frequency signal is formed from analogue quadrature I and Q channel components of a digitized signal at baseband and translated to the radio transmission frequency and for reception the radio frequency signals are transformed into I and Q quadrature analogue components at baseband and subsequently digitized.

Claims

1. A multi-mode radio transceiver comprising a sequence of bidirectional circuit modules including:

(i) a radio frequency input/output module;

(ii) a radio frequency/baseband I and Q quadrature conversion module;

(iii) an analogue/digital conversion module;

(iv) a digital signal processor;

(v) a digital signal input/output interface; and

(vi) control means whereby for transmission a radio transmission frequency signal is formed from analogue quadrature I and Q channel components of a digitized signal at baseband and translated to the radio transmission frequency and for reception a radio reception frequency signal is transformed into received I and Q quadrature analogue components at baseband and subsequently digitized, and in the quadrature module;

(a) said I channel component is applied to a circuit which generates the I channel component reciprocal, which said reciprocal is applied to one input of a first multiplier to the other input of which said Q channel component is also applied;

(b) the first multiplier output Q/I is applied to an ARCTAN circuit whose output θ

is a phase modulation version of the signal to which said I and Q channel components correspond;

(c) the ARCTAN output θ

is applied directly to one input of a first adder to the other input of which θ

is applied via a Z^-1 circuit, so that the output of the first adder is θ

, which is a frequency modulation version of the signal to which said I and Q channel components correspond;

(d) said I and Q channel components are applied respectively to two squarers whose outputs are applied to a second adder the output of which is thus (I² +Q²), which output is applied to a square root circuit whose output R is an amplitude modulation version of the signal to which said I and Q channel components correspond;

(e) for SSB the mid frequency of a sideband is applied to one input of a third adder via a summing circuit, the above-mentioned output θ

being applied to the other input of the third adder, the output of the third adder being applied via a sine-generating circuit to one input of a second multiplier to the other input of which is applied the above-mentioned output R, such that the output of the second multiplier is an SSB modulation to which said I and Q channel components correspond, and

(f) wherein of the above PM, FM, AM, SSB outputs is enabled dependent on which form of modulation is being received.

2. A quadrature conversion module for use in a radio transceiver or receiver which responds to radio frequency signals received as I and Q quadrature analogue components, which said I and Q components may represent different modulation modes, wherein:

(a) said I and Q components are applied to circuit means which generate the function Q/I, which function is applied to an ARCTAN circuit whose output θ

is a phase modulation version of the signal to which said I and Q components correspond;

(b) the ARCTAN output θ

is applied directly to one input of a first adder to the other input of which θ

is applied via a Z^-1 circuit, so that the output of the subtractor is θ

, which is a frequency modulation version of the signal to which said I and Q components correspond;

(c) said I and Q components are also applied respectively to two squarers whose outputs are all applied to a second adder the output of which is thus (I² +Q²), which output is applied to a square root circuit whose output R is an amplitude modulation version of the signal to which said I and Q components correspond;

(d) for SSB the mid-frequency of a sideband is applied to one input of a third adder via a summing circuit, the above-mentioned output θ

being applied to the other input of the third adder, the output of the third adder being applied via a sine-generating circuit to one input of a multiplier to the other input of which is applied the above-mentioned output R, such that the output of the multiplier is an SSB modulation to which said I and Q components correspond; and

(e) wherein one of the above PM, FM, AM or SSB outputs is enabled dependent on which form of modulation is being received.