| CPC H04L 27/06 (2013.01) [H04B 1/302 (2013.01)] | 14 Claims |
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1. A method for calibrating a single sideband (SSB) receiver having an input for receiving a signal, an I/Q mixer for converting the signal into an I-signal in an inphase path and a Q-signal in a quadrature path, a phase shifter for mutually phase shifting the I- and Q-signals by an adjustable phase shift, and a combiner for combining the mutually phase shifted I- and Q-signals to an SSB signal, the method comprising:
a) adjusting the phase shift to a first phase shift value;
b) successively feeding a first, a second and a third test signal to the input, the first and second test signals having a predetermined phase offset and the second and third test signals having the same predetermined phase offset, to obtain respective first, second and third SSB signals, and measuring a first phase difference between the first and second SSB signals and a second phase difference between the second and third SSB signals;
c) calculating a first phase error on the basis of the first and second phase differences;
d) repeating steps a)-c) with a second phase shift value in step a) to obtain a second phase error; and
e) calibrating the SSB receiver by using that one of the first and second phase shift values that has yielded the smaller one of the first and second phase errors.
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