Optimal Diversity Product of Code Size 6
نویسندگان
چکیده
In this correspondence, we propose some new designs of 2 2 unitary space-time codes of sizes 6; 32; 48; 64 with best known diversity products (or product distances) by partially using sphere packing theory. In particular, we present an optimal 2 2 unitary space-time code of size 6 in the sense that it reaches the maximal possible diversity product for 22 unitary space-time codes of size 6. The construction and the optimality of the code of size 6 provide the precise value of the maximal diversity product of a 2 2 unitary space-time code of size 6.
منابع مشابه
New Results In Unitary Space-Time Code Construction and Comparison to Upper Bounds
Unitary space-time codes are a coding technique for unknown (i.e. non-coherent) multiple-input multiple-output (MIMO) channels. The unitary constellation symbol-error rate performance is determined by the the diversity product and diversity sum metrics of the constellation. Numerous techniques have been presented over the last few years for constructing unitary space-time codes with continually...
متن کاملUnitary signal constellations for differential space--Time modulation with two transmit antennas: Parametric codes, optimal designs, and bounds
Differential space–time modulation has been recently proposed in the literature for multiple-antenna systems over Rayleigh-fading channels, where neither the transmitter nor the receiver knows the fading coefficients. For the practical success of differential space–time modulation, it has been shown critical to design unitary space–time signal constellations with large diversity product which i...
متن کاملSimplified sum-product algorithm for decoding LDPC codes with optimal performance
A simple, yet effective decoding algorithm is proposed for low-density parity-check (LDPC) codes, which significantly simplifies the check node update computation of the optimal sum-product algorithm. It achieves essentially optimal performance by applying scaling in the decoder’s extrinsic information. If no such scaling is applied, then the proposed algorithm has small performance degradation...
متن کاملOptimal Combined and Adaptive Protection of Active Distribution Networks Considering Different System Topologies Incorporating Optimal Selection of Standard Relay Curves
The change in the topology of active distribution networks (ADNs) is one of the essential challenges that might affect the protection schemes. The conventional protection schemes based on base topology result in some coordination constraint violations in other topologies due to the outage of upstream substations and distributed generation units. In this article, new combinational and adaptive p...
متن کاملOptical orthogonal signature pattern codes with maximum collision parameter 2 and weight 4
An optical orthogonal signature pattern code (OOSPC) finds application in transmitting 2-dimensional images through multicore fiber in code-division multiple-access (CDMA) communication systems. Observing a one-to-one correspondence between an OOSPC and a certain combinatorial subject, called a packing design, we present a construction of optimal OOSPCs with weight 4 and maximum collision param...
متن کامل