MIMO OFDM systems are very popular in 4G wireless standards because of higher spectral efficiency and reliable transmission. Long Term EvolutionAdvanced (LTE-A) standards use MIMO with a maximum of 8x8 antennas in the downlink and 4x4 antennas in uplink. In this paper a simple 2x1 MIMO system with Alamouti coding is considered. Orthogonal Space Time Block Codes (OSTBC) is mainly used to achieve...

In this paper, we propose a novel decode-and-forward dual-relay selection technique based on Alamouti space time coding for twoway wireless relay networks (TWRNs). The twoand the threephase TWRN protocol are used in the first and second version of the proposed technique, respectively, to exchange the information symbols of the communicating terminals. In order not to waste any power for transmi...

In this work, spatial diversity techniques in the area of multiple-input multiple-output (MIMO) diffusion-based molecular communications (DBMC) are investigated. For transmitterside spatial coding, Alamouti-type coding and repetition MIMO coding are proposed and analyzed. At the receiver-side, selection diversity, equal-gain combining, and maximum-ratio combining are studied as combining strate...

Although the discrete Fourier transform (DFT) precoded Alamouti (DPA) scheme with limited feedback offers numerous benefits in the Rayleigh fading channel, this scheme inherently generates geometric mean distortion due to the error exponential of the DFT precoding (DP). Consequently, the receiver suddenly losses the average received channel power. Instead of the conventional DPA scheme, we prop...

-Single-Carrier Frequency Domain Equalizer (SCFDE) scheme has several advantages than multi-carrier scheme OFDM. SC-FDE avoids all the drawbacks of OFDM. This paper analyzes the diversity gain of multi-input-multi-output (MIMO) SCFDE in frequency selective channels. This paper fully analyzes the Alamouti signaling scheme under linear equalizers such as Zeroforcing (ZF) and MMSE equalizers. The ...

In this letter, we propose a recursive space time decoding method for orthogonal frequency division multiplexing (OFDM) systems exploiting multiple transmit antenna diversity when the channels are fast fading. We first develop a computationally efficient space-time decoding method involving a matrix inversion to mitigate the channel variation effect. We then further reduce the computational com...

We present a phase-aligned space-time coding scheme that expands the original Alamouti codeword to three or four transmit antennas (Nt = 3 or 4) with phase alignment. With 1 ∼ 2 bits feedback for the phase information, the fundamental performance penalty of 10log10(Nt) dB of orthogonal space-time coding compared to the optimum beamforming is reduced by 1 dB (for Nt = 3) or 2 dB (for Nt = 4) on ...

Spatial modulation (SM) reduces transceiver complexity and inter-channel interference over traditional multiple input multiple output (MIMO) systems. It has been shown recently in the literature that the use of a precoder in an SM or a generalized spatial modulation (GSM) system can significantly improve error performance. This paper investigates two issues related to precoders: 1) the use of a...

An investigation into the wavelet packet transform (WPT) modulation scheme for Multiple Input Multiple Output (MIMO) band-limited systems is presented. The implementation involves using the WPT as the base multiplexing technology at baseband, instead of the traditional Fast Fourier Transform (FFT) common in Orthogonal Frequency Division Multiplexing (OFDM) systems. An investigation for a WPT-MI...

This paper focuses on blind channel estimation in Alamouti coded systems with one receiving antenna working in indoor scenarios where the flat fading assumption is reasonable. A comparative study of several channel estimation techniques in both simulated and realistic scenarios is presented. The tested methods exploit the orthogonality property of the Alamouti coded channel matrix, and are base...