Title: A Construction of 2-D Z-Complementary Array Code Sets with Flexible Even Row Lengths and Applications in Massive MIMO

Abstract: The need for two-dimensional (2-D) arrays with good 2-D correlation properties and flexible parameters has been of great interest due to their application in the field of wireless communications such as massive multiple input multiple output (MIMO), phased array antenna, multi-carrier code division multiple access (MC-CDMA), 2D-MC-CDMA, etc. In this paper, we propose a direct construction of a 2-D Z-complementary array code set (ZCACS) with flexible parameters. For this purpose, we first propose a construction of inter-group complementary (IGC) code sets using multivariable function and by using this construction 2-D Z-complementary array code (ZCAC) and 2-D ZCAC set (ZCACS) are provided. In some special case, the proposed 2-D ZCAC reduces to a 2-D Z-complementary array pair (ZCAP), which is not reported till date. The peak-to-mean envelope power ratio (PMEPR) of row and column sequences of 2-D ZCAC is shown to be better than the existing ones for use in MC-CDMA. 2-D Golay complementary array set (GCAS) and Golay complementary set (GCS) are derived from the proposed construction, which can be applied in omnidirectional precoding (OP) based transmission through massive MIMO. The proposed construction can support a more flexible number of antennas for a uniform rectangular array (URA) to transmit space-time block coded (STBC) data, than the existing constructions. The bit-error-rate (BER) simulation result also shows the performance benefits of derived 2-D GCAS and GCS compared to the existing ones.