Interference cancellation in adjoint operators for communication receivers

摘要

A receiver in a wireless communication system comprises a reverse transform configured to produce a vector of baseband signal values, and a projection canceller configured to project the vector of baseband signal values onto at least one subspace that is substantially orthogonal to an interference subspace. The reverse transform may be adjoint to a forward transform employed by at least one transmitter in the wireless communication system. The combination of interference cancellation with one or more receiver operations may be a substantially adjoint operation relative to one or more transmitter operators and channel-propagation effects. The reverse transform may include a Fourier transform, a wavelet transform, or any other well known invertible transforms. Reverse transforms may include spread-spectrum multiple-access coding and may be implemented in systems configured to perform single-input, multiple output or multiple-input, multiple-output operations. Interference components may be selected in a projection canceller relative to predetermined ratios of interference in the received signal.