  The $K$-user single-input single-output (SISO) AWGN interference channel and
$2\times K$ SISO AWGN X channel are considered where the transmitters have the
delayed channel state information (CSI) through noiseless feedback links.
Multi-phase transmission schemes are proposed for both channels which possess
novel ingredients, namely, multi-phase partial interference nulling,
distributed interference management via user scheduling, and distributed
higher-order symbol generation. The achieved degrees of freedom (DoF) values
are greater than the best previously known DoFs for both channels with delayed
CSI at transmitters.
