Transmitter and method of generating a transmission signal
AssigneeKoninklijke Philips Electronics N.V.
InventorsWinfrid Birth, Andreas Fröhlich
Life of this patent
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Abstract
The invention relates to a transmitter and a method of generating a transmission signal. A first modulation device 12 generates an uncompensated transmission signal Y(t) by modulating at least one baseband signal I, Q with a respective oscillation signal LOQ, LOI. The invention improves a transmitter with such a modulation device so as to reduce the expenditure for the filtering at a later stage that is necessary to attenuate undesirable components in the uncompensated transmission signal Y(t). This is achieved in that a compensation signal C(t) is formed on the output of a second modulation device (14), the compensation signal representing essentially the components to be compensated in the uncompensated transmission signal Y(t).
Claims9
A transmitter for generating a transmission signal Y(t), said transmitter comprising:
- a first modulation device (12) for generating an uncompensated transmission signal Y(t) by modulation of at least one baseband signal I, Q with a respective oscillation signal LOQ, LOI;
- and a second modulation device (14) for generating a compensation signal C(t), representing essentially the components to be compensated in the uncompensated transmission signal Y(t), by modulation of the baseband signal I, Q with an auxiliary oscillation signal 3LOQ, 3LOI, and
- a subtraction device (18) for subtracting the compensation signal C(t) from the uncompensated transmission signal Y(t) and for delivering an at least partly compensated transmission signal Y′(t).
A method of generating a transmission signal y′(t) which includes the following steps:
- generating an uncompensated transmission signal y(t) by modulating at least one baseband signal I, Q with a respective oscillation signal LOQ, LOI,
- characterized in that a compensation signal C(t) is generated by modulating the baseband signal I, Q with an auxiliary oscillation signal 3LOQ, 3LOI,
- the compensation signal representing essentially the components to be compensated in the uncompensated transmission signal Y(t), and the compensation signal C(t) being subtracted from the uncompensated transmission signal Y(t) in order to generate an at least partly compensated transmission signal Y′(t).
Dependencies are inferred from the claim text.