Link adaptation is a crucial part of many modern communications systems, allowing the system to adapt the transmission and reception strategies to changes in channel conditions. One of the fundamental components of the link adaptation mechanism is signal to noise ratio (SNR) estimation, measuring the instantaneous (mostly post processing) SNR at the receiver. That is, the SNR at the decoder inp...

A multiple-input multiple-output (MIMO) system consists of multiple antennas at the receiver and transmitter. These multiple antennas can be used to improve the performance of the system through spatial diversity or increase the data rates by spatial multiplexing. One can also use some of the antennas for diversity and some for spatial multiplexing. The number used for diversity and spatial mul...

A novel compressive-sensing based signal multiplexing scheme is proposed in this paper to further improve the multiplexing gain for multiple input multiple output (MIMO) system. At the transmitter side, a Gaussian random measurement matrix in compressive sensing is employed before the traditional spatial multiplexing in order to carry more data streams on the available spatial multiplexing stre...

In this paper Multiple Active Spatial Modulation (MA-SM) is proposed as an alternative to Space Time Block Code (STBC), Vertical Bell Lab Layered Space Time (V-Blast) etc with multiple active transmit antennas. To achieve high transmit rate, it allows several antennas to be active simultaneously. The symbols are mapped into a high dimensional constellation space including the spatial dimension....

Wireless links with multi-antenna transmitters and receivers can be used to provide increased diversity and/or large data-rates. It has been shown that multi-antenna communication systems can simultaneously achieve the maximum diversity and maximum rate (or multiplexing) gain. This paper proposes a modified version of traditional spatial multiplexing that allows the wireless system to obtain ma...

Currently Modeling Indoor channel is an active research area and is used in a wide variety of applications such as voice over IP (VoIP), streaming video and music and network attached storage. These applications use MIMO for controlling the IR based system using LED’S and PD’S.In Multiple-Input Multiple-Output (MIMO) systems, a multiple-stream transmission takes place between a base station (BS...

Multiple Transmit and receive antenna are now popularly used to form multiple input, multiple output (MIMO) channels to increase the capacity as well as to reduce the Bit Error Rate (BER). This paper describes the performance of Hybrid MIMO-OFDM (Orthogonal Frequency Division Multiplexing) models, which are developed & analyzed in Matlab ® Simulink. In this study 2×2 STBC-OFDM and 2×2 SM-OFDM s...