Perfect Space–Time Codes for Any Number of Antennas

In a recent paper, perfect $(n \times n)$ space–time codes were introduced as the class of linear dispersion space–time (ST) codes having full rate, nonvanishing determinant, a signal constellation isomorphic to either the rectangular or hexagonal lattices in $2n^2$ dimensions, and uniform average transmitted energy per antenna. Consequence of these conditions include optimality of perfect codes with respect to the Zheng–Tse diversity–multiplexing gain tradeoff (DMT), as well as excellent low signal-to-noise ratio (SNR) performance. Yet perfect space–time codes have been constructed only for two, three, four, and six transmit antennas.