  In this letter, following a cross-layer design concept, we propose a novel
subcarrier grouping technique for Orthogonal Frequency and Code Division
Multiplexing (OFCDM) multiuser systems. We adopt a two dimensional (2D)
spreading, so as to achieve both frequency- and time-domain channel gain.
Furthermore, we enable a receiver-centric approach, where the receiver rather
than a potential sender controls the admission decision of the communication
establishment. We study the robustness of the proposed scheme in terms of the
Bit-Error-Rate (BER) and the outage probability. The derived results indicate
that the proposed scheme outperforms the classical OFCDM approach.
