Preamble structures for single-input, single-output (SISO) and multi-input, multi-output (MIMO) communication systems

A frame transmitted in a communication system, the frame comprising:

• at least one signal structure, each signal structure comprising a preamble structure having a first time length and a data structure having a second time length, each signal structure being transmitted by a corresponding transmit antenna;
• each preamble structure comprising at least one training symbol, each of the at least one training symbol having a third time length, each of the at least one training symbol comprising a first cyclic prefix having a time length G and a training block having a time length NI;
• and
• each data structure comprising at least one data symbol, each of the at least one data symbol having a fourth time length, each of the at least one data symbol comprising a second cyclic prefix having time length G and a data block having a time length N;
• wherein N1 is a first integer fraction of N, and G is a second integer fraction of NI.