A Square Complex OSTBC with Low PAPR for 16 Antennas

Square Complex Orthogonal Space Time Block Codes (COSTBC) with no zero entries are known for 2,4 and 8 transmit antennas. But, for 16 transmit antennas COSTBCs with no zero entries have not been reported. Zero entries in the design lead to the problem of switching off of transmit antenna, imposing severe constraints on hardware implementation. The zeros also result in the increase of the Peak to Average Power Ratio (PAPR). The COSTBCs constructed for 16 transmit antennas from representations of Clifford algebras have 68.75% of zero entries and the Adams-Lax-Phillips construction, Jozefiak construction and Wolfe construction lead to designs with 43.75% of entries zeros, as the construction methods involve identity matrices. Recently, a COSTBC for 16 transmit antennas containing 37.5% zeros have been reported. In this paper, a construction method of COSTBC for 2 antenna codes, with a ≥ 4 is proposed which gives a square COSTBC of order 16 having only 25% zero.