Inspec keywords: matrix algebra; least mean squares methods; wireless channels; OFDM modulation; error statistics

Other keywords: Toeplitz stair block diagonal matrices; Ramanujan periodic subspace division multiplexing; integer-valued Ramanujan sum; linear time-invariant wireless channels; orthogonal frequency division; Ramanujan subspaces; RPSDM; structured subspaces representation

Subjects: Interpolation and function approximation (numerical analysis); Interpolation and function approximation (numerical analysis); Radio links and equipment; Other topics in statistics; Modulation and coding methods