TRANSMITTER CIRCUIT, COMMUNICATION UNIT AND METHOD FOR AMPLIFYING A COMPLEX QUADRATURE SIGNAL

摘要

A transmitter circuit includes a frequency generation circuit configured to generate a local oscillator signal and a digital modulator configured to: receive data to be transmitted; quadrature modulate the received data to at least a first, Q, modulated value and a second, I, modulated value; examine the quadrature modulated data to determine if the first, Q, modulated value exceeds a limit, and in response thereto selectively modify the quadrature modulated values to a first modified, Q′, modulated value and a second modified, I′, modulated value thereby bringing only a value of the first modified, Q′, modulated value to within the limit. A local oscillator phase is selected in order to map the first modified, Q′, modulated value and second modified, I′, modulated value to desired quadrature values. A digital power amplifier, DPA, coupled to the digital quadrature modulator, is configured to amplify the quadrature modified modulated data.

主权项

1. A transmitter circuit comprising:
a frequency generation circuit configured to generate a local oscillator signal; and a digital quadrature modulator coupled to the frequency generation circuit and configured to:
receive data to be transmitted;quadrature modulate the received data to at least a first, Q, modulated value and a second, I, modulated value;examine the quadrature modulated data to determine if the first, Q, modulated value exceeds a limit, and in response theretoselectively modify the quadrature modulated values to a first modified, Q′, modulated value and a second modified, I′, modulated value thereby bringing only a value of the first modified, Q′, modulated value to within the limit;select and apply a phase of the local oscillator signal to map the first modified, Q′, modulated value and second modified, I′, modulated value to desired quadrature values.