Method and apparatus for efficient transmit diversity using complex space-time block codes

The present invention relates to transmit diversity in wireless transmitters and communication systems. More particularly, the present invention relates to a method and apparatus for increasing transmit diversity efficiency using complex orthogonal space-time block codes. Transmitting a signal in a transmit diversity wireless communication system using 4 antennae, using a complex, multilevel orthogonal space-time code of dimension 4×n, and length p=n. In an exemplary embodiment the method includes the steps of: configuring a first row of a multilevel orthogonal 4×n matrix Gas an arbitrary cyclic version of a Generalized Chirp-Like (GCL) sequence of length n; configuring a second row of a multilevel orthogonal 4×n matrix Gas the complex-conjugated version of the first row having inverted signs of the first n/2 or the last n/2 out of n consecutive symbols in the first row; configuring a third row as a reverted version of the first row; and, configuring a fourth row as a complex-conjugated version of the third row having inverted signs of a first n/2 or a last n/2 out of n consecutive symbols in the third row.