Compressed Sensing-Aided Index Modulation Improves Space-Time Shift Keying Assisted Millimeter-Wave Communications

摘要： In this treatise, we present the concept of Compressed-Sensing (CS)-aided Space-Time Shift Keying Index Modulation (STSK-IM), where a virtual domain Orthogonal Frequency Division Multiplexing (OFDM) symbol is divided into Na-sized blocks, which carry K STSK codewords over a specific combination of virtual-domain sub-carriers and then converted to the frequency domain with the aid of a CS matrix. We design the system for operation in the Milli-meter Wave (mmWave) frequency band. Furthermore, we amalgamate our soft-decision-aided scheme both with the concept of Coordinate-Interleaving (CI) as well as a Discrete Fourier Transform (DFT)-aided codebook design conceived for analogue beamforming, which is vitally important for mmWave systems. In the proposed system, the number of implicit bits conveyed by the activated sub-carrier Frequency Index (FI) is determined by the number of the available K to Na sub-carrier permutations. Hence, we propose two FI allocation techniques, namely the Distinct FI (DFI) and the Shared FI (SFI) based schemes, which strike a trade-off between the attainable sparsity level and the achievable capacity limit. We then introduce a reduced-complexity detection technique in order to mitigate the detection complexity to order of the optimum detector from O(Nc · (Q · L)K) to O(?Nc · (Q · L)K), where ?Nc ≤ Nc. We also formulate the Discrete-Input Continuous-Output Memoryless Channel (DCMC) capacity and invoke EXtrinsic Information Transfer (EXIT) charts for characterizing the achievable performance limit of the reduced-complexity aided detector. Finally, we analyze the BER performance of both the uncoded and of our coded CS-aided STSK-IM systems associated with both the optimum and the reduced-complexity detectors.