Blind classification of modulation scheme of an interfering signal

A wireless receiver apparatus, comprising:

• a receiver circuit that receives an orthogonal frequency division multiplexing (OFDM) signal on a shared downlink channel from a wireless network, the OFDM signal including contribution from a serving cell signal and at least one interfering signal;
• and
• a processor that processes the received OFDM signals by:
• obtaining an estimate of the serving cell signal;
• calculating a residual signal by subtracting the estimate of the serving cell signal from the OFDM signal;
• generating a whitened residual signal by whitening the residual signal;
• obtaining an estimate of a modulation scheme of the at least one interfering signal by performing a likelihood-based blind classification on the whitened residual signal;
• and
• performing further receiver-side processing of the serving cell signal using the estimate of the modulation scheme of the at least one interfering signal.

A method of wireless signal processing performed at a receiver in a wireless network, comprising:

• receiving a signal that includes a desired signal, which carries information intended to be received, and an interfering signal, which is an undesired signal superimposed on the desired signal;
• obtaining a residual signal by subtracting the desired signal from the received signal;
• and
• determining a modulation scheme of the interfering signal using a likelihood calculation procedure based on certain constellation points of a first candidate modulation scheme having minimum distances from constellation points of the residual signal and based on corresponding constellation points of a second candidate modulation scheme closest to the constellation points of the first candidate modulation scheme.