Device, system, and method of resource allocation in a wireless network. Embodiments include optimal space-frequency architectures for very high peak rates in wireless systems. For example, an apparatus for wireless communication in a power-limited, very wideband system includes a wireless communication device having a media access controller (MAC) and a physical layer (PHY) that are adapted for a multiple-input-multiple-output (MIMO) orthogonal frequency-division multiple access (OFDMA) communication scheme; a plurality of antennas, operationally coupled to said device, to send and receive wireless communication signals according to the MIMO-OFDMA communication scheme; and a resource allocator, to allocate transmission resources of the device into desired MIMO channels optimized according to at least one of signal-to-noise ratio (SNR), bandwidth, number of users, and signal-to-noise-plus-interference ratio (SINR).