The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In a MIMO wireless communications system, a space-time block code specifies how the data symbols are transmitted over different antennas at different time instants. A hybrid space-time code attempts to obtain some of the available diversity and multiplexing gains, achieving low error probability and high data rate. The LD StBc-VBLAST hybrid code layers one spatial-multiplexing antenna (to increase...
A simple technique to design MIMO space-time block codes that achieve both diversity and rate gains is to stack spatial multiplexing (V-BLAST) and transmit diversity (Alam-outi) encoders; these are known as hybrid codes. We increase the spectral efficiency of a simple hybrid code with one V-BLAST layer and one Alamouti layer by using spatial modulation. In spatial modulation systems, information is...
Wireless powered communications is a promising technology for next-generation low-powered sensor networks such as the Internet of Things. This paper deals with backscatter communications in sensor networks, an ideal technology for low-powered battery-less devices. However, in contrast to conventional communications, backscattering suffers from collisions due to multiple concurrent transmissions and...
The problem of high-rate space-time block code (STBC) design and transmission is studied in a large multiple-input multiple-output (MIMO) system in Rayleigh fading environment. One attractive feature of large MIMO system is that a huge amount of data can be transmitted from transmitter to the receiver/multiple users. In practical systems, channel state information (CSI) is not available for decoding...
In multiple-input multiple-output (MIMO) two-way relay networks (TWRN), linear physical-layer network coding (LPNC) was proposed to boost the throughput by using spatial multiplexing at source nodes. How to design optimal LPNC for full-rate full-diversity MIMO TWRN is still an open problem. In this paper, we propose a full-rate full-diversity (FRFD) LPNC scheme. In this scheme, two source nodes, each...
Incorporating the effect of residual self-interference, the spectral efficiency (SE) of full-duplex relay channel is analyzed for different relay schemes. The optimal relay power and the corresponding optimal SE have been derived in closed form for decode-forward, compress-forward, and amplify-forward (AF) schemes. In particular, backward decoding is introduced to the AF scheme in the presence of...
Real interference alignment is efficient in breaking-up a one-dimensional space over time-invariant channels into fractional dimensions. As such, multiple symbols can be simultaneously transmitted with fractional degrees-of-freedom (DoF). Of particular interest is when the one dimensional space is partitioned into two fractional dimensions. In such scenario, the interfering signals are confined to...
Multiple-input multiple-output (MIMO) is an essential technology for modern wireless communication systems. Spatial modulation (SM) is an evolving MIMO transmission scheme for energy-efficient massive MIMO systems. SM conveys the information of transmit antenna indices and modulated symbols in MIMO systems. A variant spatial permutation modulation (SPM) was further proposed to include transmit and...
In this work, we consider the problem of data decoding in media-based modulation systems. The underlying problem is sparse because only a subset of the available transmit antennas is activated in each symbol; additionally, only one of the different mirror patterns is activated depending on the unknown data bits. Thus, the data recovery problem involves recovery of a block-sparse vector, with the additional...
Much attention has been paid to higher frequency (HF) radio communication providing large capacity. As well, maintaining its communication quality is one of the crucial issues, and diversity approaches should be effective ways in terms of physical layer. Differential Space-Time Block Coding (DSTBC), which is a spatial diversity strategy, has robustness against phase noise serious in a HF band. Employing...
the complexity of sphere detection algorithm is high when the Signal to Noise Ratio (SNR) is low. For this problem, a new type of detection algorithm of sphere decoder is proposed. The new algorithm reduces the radius of sphere when the SNR is low by using the Minimum Mean Square Error (MMSE) algorithm and a compressibility factor. With the result of simulation, It shows that when the SNR is less...
In this paper, a new cooperative spectrum sharing protocol that employs space-time block coded spatial modulation (STBC-SM) at the secondary user (SU), is proposed for overlay cognitive radio (CR) networks. STBC-SM is applied at the secondary transmitter (ST) which transmits its data by both modulated symbols and antenna combinations while conveying PU's data only by modulated symbols. This protocol...
In this paper, a down-link cooperative communication scheme is proposed using full-rate Quasi-Orthogonal Space-time Block Codes (QOSTBC), employing asynchronous mobile Decode and Forward (DF) relays in a Rayleigh fading wireless environment. The channel used is a partially-coherent relay channel (PCRC), where the first hop is non-coherent and the second is coherent. Base station broadcasts using four...
In this paper, we characterize the asymmetric total degrees of freedom (DoF) of a multiple-input multiple-output (MIMO) 3-way channel. Each node has a separate-antenna full-duplex MIMO transceiver with a different number of antennas, where each antenna can be configured for either signal transmission or reception. Each node has two unicast messages to be delivered to the two other nodes. We first...
Sparse code multiple access (SCMA) is a novel kind of air interface technology which can dramatically improve spectral efficiency of wireless radio access. Different from conventional CDMA and OFDMA, SCMA achieves the non-orthogonal multiple access of frequency domain. On the other hand, Multiple-Input Multiple-Output (MIMO) can make full use of spatial-domain resource to improve system performance...
In this paper we consider a novel design of space-time block code combined with pre-coding module transmission system. Theory of orthogonal designs has shown that such code cannot be simultaneously orthogonal, of rate 1, with full diversity order, for more than 2 transmit antennas. We propose in this paper a new way to overcome this limitation by adding a pre-coding module before transmitting space-time...
There has been a rejuvenated interest in the use of arbitrary constellations (non-equally spaced) after promising performance results were demonstrated compared to conventional grid and circular constellations. To enable the development of such constellations, in this contribution we derive an upper bound bit-error-rate (BER) expressions for coded transmit maximum ratio combining (TMRC) systems operating...
Polar codes are known as the first provable code construction to achieve Shannon capacity for arbitrary symmetric binary input channels. Several schemes to provides both detection/decoding of the transmitted and the transmit antenna index in Multiple-Input Multiple-Output (MIMO) antenna systems were proposed in the literature for polar codes. In this paper we have critically analyzed various MIMO...
The multiple input multiple output (MIMO) technology combined with orthogonal frequency division multiplexing (OFDM) is a dominant air interface technology for 4G and 5G wireless communication technologies. In this paper we proposed a new threshold based soft partial parallel interference canceller for MIMO-OFDM system. The MIMO detector based on the hybrid use of soft minimum mean square error (MMSE)...
In wideband communication systems, Multi-Input Multi-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) has been proposed as an efficient technique to enhance the link reliability and the spectral efficiency. However, the high Peak to Average Power Ratio (PAPR) of the output signals degrades the advantage of the MIMO-OFDM systems. In order to overcome this issue, several methods requiring...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.