High-rate space-time block coding scheme is constructed for multiple-input multiple-output (MIMO) Rayleigh fading channels. It employs the D-blast transmission scheme combined with lattice constructions tailored for the number of transmit and receive antennas, transmission rate and signal-to-noise ratio. The lattices are constructed with the aid of performance-optimizing criteria, and the obtained coding scheme is rate-preserving, i.e. the bandwidth and information rate of the original D-blast scheme are maintained. The scheme is rich in structure and can therefore provide good tradeoff between coding gain and decoding complexity. Its advantages are more pronounced as the number of antennas increase.