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In this paper, we extend the idea of Index modulated orthogonal frequency division multiplexing (IM-OFDM) to the MIMO scenario and propose the precoded index modulation for multi-input multi-output OFDM (PIM- MIMO-OFDM) for downlink transmission. Based on the channel state information (CSI) at the transmitter, PIM-MIMO-OFDM jointly selects the active elements of the receiver-side space-frequency OFDM...
In LTE-Advanced (LTE-A) demodulation reference symbols are employed for pilot aided channel estimation to perform coherent detection. Since these reference symbols are allocated on the same time-frequency positions for all users in Multi-User MIMO (MU-MIMO) operation or for all spatial layers in Single-User MIMO (SU-MIMO), they are designed to be code-domain orthogonal in order to be separable at...
In this paper, we investigate the performances of schedulers, which basically allocate the resources to multiple users based on different algorithms, in multiple-input multiple-output (MIMO) and orthogonal frequency division multiple access (OFDMA) based cellular wireless networks. In addition to conventional OFDMA resources which are time and frequency, antennas are also considered as resource during...
The combination of singular value decomposition (SVD)-based beamforming and filter bank multicarrier with offset quadrature amplitude modulation (FBMC/OQAM) has not been successful to date. The difficulty of this combination is that, the beamformers may change dramatically between adjacent subchannels, therefore destroy the orthogonality of FBMC/OQAM real-valued symbols, under frequency selective...
In this paper, we propose the uplink transceiver for Subcarrier Index Modulation (SIM) OFDM in multiuser massive MIMO systems with imperfect channel state information (CSI). In the proposed scheme, the indexes of inactive subcarriers implicitly transmit information bits and the subcarriers activation process is only dependent on modulation order of M-QAM. To mitigate multiuser interference at the...
In this paper, we propose a phase noise cancellation algorithm in MIMO-OFDM systems where each transmit (TX) and receive (RX) antenna is equipped with independent oscillator. Most of previous works have considered phase noise model only in SISO-OFDM or simplified phase noise model in MIMO systems assuming that each TX and RX end shares one local oscillator. Recently, however, the local oscillator...
We have been researching a transmission system that uses high-order carrier modulation with orthogonal frequency division multiplexing (OFDM) and dual-polarized multiple-input multiple-output (MIMO) for 8K Super Hi-Vision terrestrial broadcasting. We evaluated the transmission performance of non-uniform QAMs (NUQAMs) with a simplified demapping algorithm that approximates the log-likelihood ratio...
In this paper, the extension of the orthogonal frequency division multiplexing (OFDM) index modulation (IM) from single-antenna systems to multiple-antenna systems is studied. And a multiple-input multiple- output (MIMO) OFDM IM scheme with circular-shift-based activation pattern is proposed for the rapidly time- varying (RTV) channel. In the proposed scheme, the IM is applied in the joint antenna...
In this paper, we propose a generalized light emitting diode (LED) index modulation scheme for multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) visible light communications (VLC) systems. The proposed scheme generalizes the LED index modulation concept by using the spatial multiplexing principle to transmit complex OFDM signals through VLC channels by separating...
In this paper a novel low complexity scheme that achieves also reduced feedback overhead is studied for reporting the channel state information in Carrier aggregation MIMO systems. Such systems usually involve a large number of carriers and users, so the calculation and reporting of the required RI/PMI/CQI indexes could result in high computational complexity and feedback overhead. Given that the...
Based on the orthogonality of space-time (ST) code, this paper concentrates on ST code transmission combined with intercarrier interference (ICI) parallel cancellation (PC) scheme to form STPC systems. With known channel state information (CSI) and orthogonal frequency division multiplexing (OFDM), we further develop this STPC-OFDM system with code rates 1 and 0.5 without increasing in power, bandwidth,...
Massive Multiple-Input and Multiple-Output (MIMO) technology that employs a very large number of antennas at the base station (BS), serves relatively fewer users jointly and simultaneously. Adaptive transmission technique in a large-scale MIMO wireless communication systems, can further enhance the reliability of the transmission links and improve the spectrum efficiency. This paper is based on beam...
A novel noise whitening technique of blind subspace channel estimations is proposed for cyclic prefixing multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. A fast convergence subspace channel estimation for cyclic prefixed MIMO-OFDM systems was presented in [1] where the repetition index was used to increase the number of equivalent received signals. However,...
In this paper, a new low complexity successive interference cancellation (SIC) technique is proposed for a QPSK mapping multiple-input multiple-output (MIMO) spatial multiplexing system based on a Quadratic Programming detector (QP-SIC). The proposed technique uses Log-Likelihood ratio (LLR) for reliability ordering of received symbols, and then formulates SIC procedures using a QP formulation. Simulation...
Spatial modulation (SM) is a promising single frequency-radio (RF) large-scale multiple-input multiple-output (MIMO) technique which can strike an attractive tradeoff between spectral efficiency (SE) and energy efficiency (EE) of a wireless network. Recently, a novel technique termed as orthogonal frequency division multiplexing with index modulation (OFDM-IM) emerges, where the SM principle is applied...
In this paper, a software-based implementation for the Multiple Input and Multiple Output (MIMO) receiver baseband processing conforming to the IEEE 802.11ac standard on a DSP core with vector extensions is presented. The implementation is carried out for different operation points including 2×2 and 4×4 MIMO configurations, yielding beyond 1Gbps transmission bit rate. This implementation mainly focuses...
This paper proposes a parametric channel estimation method for massive multiple input multiple output (MIMO) systems, whereby the spatial correlation of wireless channels is exploited. For outdoor communication scenarios, most wireless channels are sparse. Meanwhile, compared with the long signal transmission distance, scale of the transmit antenna array can be negligible. Therefore, channel impulse...
In this paper, we proposed the addition of 2 new bits in Downlink Control Information (DCI) format 2D used for Transmission Mode 10 in 3GPP LTE-A specification. This New Downlink Control Information Design with two new bits extends the Downlink Demodulation Reference Signal (DMRS) so that the Physical Downlink Shared Channel (PDSCH) shall be processed and mapped to Resource Elements (RE) mapping and...
Modern MIMO RF transceiver systems are designed to operate reliably under diverse channel conditions leading to incorporation of significant performance margins in RF transceiver systems. In general, across dynamically varying channel conditions, the fidelity of the RF front end devices can be traded-off against power consumption without compromising system-level BER limits. In this work such a real-time...
MIMO OFDM is a key technique for achieving high data rate in future wireless communication systems. The desired low-cost, low-power and fully integrated implementation of MIMO OFDM systems leads to the application of direct (up/down) conversion architecture, whose performance can be seriously limited by I/Q-imbalance. Thus, the compensation of I/Q-imbalance is a crucial issue in the implementation...
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