Method and apparatus for data transmission using multiple transmit antennas

A method of communicating that, for transmitting a digital signal, employs a plurality of n antennas and employs a multi-level structured space-time code with encoders at each level having a trellis structure, comprising the steps of:

• selecting branches of the trellises at different levels, and selecting constellation points based on the label of the selected branches and some set partitioning of the constellation;
• and
• transmitting the signal constellation points corresponding to the branch labels of the selected branches over the plurality of antennas simultaneously.

An apparatus for transmitting a digital signal using a plurality of n antennas, comprising:

• an encoder unit employing a code having a trellis structure such that the branches of the trellis correspond to n elements of a signal constellation, the encoder unit selecting a branch of the trellis based on input data, and a previous state of the encoder unit;
• and
• a transmitter unit, for simultaneously transmitting said n elements of the signal constellation corresponding to the selected branch over n plurality of antennas, respectively.

An apparatus for transmitting a digital signal using a plurality of n antennas, comprising:

• a multi-level structured space-time code encoder unit, the encoder unit at each level having a trellis representation, and selecting (a) branches of the trellises at different levels, and (b) constellation points based on labels of the selected branches;
• and
• a transmitter unit, for transmitting the signal constellation points corresponding to the branch labels of the selected branches over the plurality of antennas simultaneously.

An apparatus for transmitting a digital signal using a plurality of n antennas, comprising:

• an encoder unit for encoding the digital signal using an outer error-correcting code, and encoding the output of the outer error correcting code using an inner space-time code;
• and
• a transmitter unit, for transmitting the code symbols of the space-time code simultaneously using said n antennas, and pilot symbol sequences during certain time intervals in lieu of said code symbols to test transmission conditions of channel over which said n antennas transmit.