2013/09/10 by Abhinav Ganesan, Ganesan, Abhinav, B. Sundar Rajan +1
Computer Science · Engineering · Mathematics · #Advanced MIMO Systems Optimization #Antenna Design and Analysis #Cooperative Communication and Network Coding #FOS: Computer and information sciences #Information Theory (cs.IT) #cs.IT #math.IT
paper · pdf · doi:10.48550/arxiv.1309.2473
11 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1304.1432
arxiv created 2013/09/10 · openalex publication_date 2013/09/10 · arxiv updated 2013/09/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Interference alignment is known to achieve the maximum sum DoF of (4M)/(3) in the 2 × 2 X-Network (i.e., two-transmitter (Tx) two-receiver (Rx) X-Network) with M antennas at each node, as demonstrated by Jafar and Shamai. Recently, an Alamouti code based transmission scheme, which we call the Li-Jafarkhani-Jafar (LJJ) scheme, was proposed for the 2 × 2 X-Network with two antennas at each node. This scheme achieves a sum degrees of freedom (DoF) of (8)/(3) and also a diversity gain of two when fixed finite constellations are employed at each Tx. In the LJJ scheme, each Tx required the knowledge of only its own channel unlike the Jafar-Shamai scheme which required global CSIT to achieve the maximum possible sum DoF of (8)/(3). Bit error rate (BER) is an important performance metric when the coding length is finite. This work first proposes a new STBC for a three transmit antenna single user MIMO system. Building on this STBC, we extend the LJJ scheme to the 2 × 2 X-Network with three antennas at each node. Local channel knowledge is assumed at each Tx. It is shown that the proposed scheme achieves the maximum possible sum DoF of 4. A diversity gain of 3 is also guaranteed when fixed finite constellation inputs are used.