Special Block Coding for Spatial Modulation

In this paper, we introduce a block coding technique for the spatial modulation with more protection assigned to the antenna selection bits. After decoding process, the corrected antenna indices are fed back to the maximum likelihood detector to detect the new related transmitted message which achieves high Bit Error Rate (BER) performance with relatively low redundanc

Deep Fading Effect On an Individual Link of 4× 4 Mimo Communication Systems

The hottest issue of next generation communication systems is data throughput improvement for any wireless channel conditions. Mul-ti-Input Multi-Output (MIMO) systems are the key technology for the next generation communication systems. Bill Lab Layered Space Time (BLAST) system achieves high data rates with acceptable BER performance over a good channels state. However, when the wireless channel has a considerable fading then the performance will be decreased and at a deep-fading state the system may fail to transmit any signal. This paper studies and compares the conventional 4 4 Vertical BLAST system capacity and bit error rate (BER) performance at Maximum Likelihood (ML) receiver through a simulation. It also studies the effect of a transmit link deep-fading on the effective signal to noise ratio, system BER and system capacity in 4 4 VBLAST system in a comparative way with the conventional 4 4, 3 4, 2 4 and 1 4 VBLAST system. Considering that every possible case of transmit link deep fade lower than-20dB fading gain is equivalent to switching off this transmit link an

Performance Evaluation of MIMO Spatial Multiplexing Detection Techniques

Multiple Input Multiple Output (MIMO) multiplexing is a promising technology that can greatly increase the channel capacity without additional spectral resources. The challenge is to design detection algorithms that can recover transmitted signals with acceptable complexity and high performance. In this paper, several MIMO Spatial Multiplexing (SM) detection techniques are introduced and evaluated in terms of BER. Different aspects have been considered and discussed in this evaluation such as; signal to noise ratio, number of transmit and receive antennas. The performance comparisons and graphs have been generated using an optimized simulator. This simulator has been developed using MATLAB®

Two-group decodable distributed differential space-time code for wireless relay networks based on SAST codes 2

Space-time code can be implemented in wireless relay networks when all relays cooperate to generate the code at the receiver. In this case, it is called distributed space-time code. If the channel response changes very quickly, the idea of differential space-time coding is needed to overcome the difficulty of updating the channel state information at the receiver. As a result, the transmitted signal can be demodulated without any knowledge of the channel state information at the relays or the receiver. In this paper, development of new low decoding complexity distributed differential space-time codes is considered. The developed codes are designed using semiorthogonal algebraic space-time codes. They work for networks with an even number of relays and have a two-group decodable maximum likelihood receiver. The performance of the new codes is analyzed via MATLAB simulation which demonstrates that they outperform both cyclic codes and circulant codes

Meander Line and E-shape Antenna’s Parameters Enhancement For WLAN Applications

The meander line antennas (MLA) are electrically small antennas that pose several performance related issues such as narrow bandwidth, low gain and high cross polarization levels. In this research enhancement techniques were applied to enhance the gain and the bandwidth of one MLA antenna. Antenna gain of 2.78dB at the resonant frequency of 2.5 GHz, the bandwidth is 440MHz, and return loss is-50dB. Furthermore, a shape modification to E-shape was applied on the antenna resulted in a small antenna gain and significant increase in the bandwidth

Set Partitioning to Construct Block Coded Modulation with the Presence of Spatial Modulation in MIMO Systems

In this paper, enhancing the BER performance of multiple-input multiple-output systems (MIMO) is considered by using Block Coded Spatial Modulation (BCSM). It is a combination of Block Coded Modulation (BCM) used set partitioning to formulate the code, and the spatial Modulation (SM) as a transmission technique of MIMO systems. To achieve this, the idea of MIMO communication systems, block coded modulation, set partitioning, multi stage decoding and spatial modulation have been combined. Matrix Laboratory (MATLAB) is used for the simulation and Bit Error Rate (BER) is obtained and verified. The simulation results for the combination of BCM with SM show that there is a significant improvement in BER performance compared to the classical SM techniques. It gives an approximately 5 dB enhancing of BER performance from the use of SM only, and about 3 dB enhancing from the use of coded information bits with SM

Triple-band HTS filter using dual spiral resonators with capacitive-loading

The increasing demand on microwave spectrum for communication systems has been the driving force in the filter industry. Multiple filtering characteristics have become necessary for many filter designs in mobile and satellite applications. In this paper, a new cost-function for an optimization algorithm to achieve a multiple passband filtering function has been introduced. A high-temperature superconductor ten-pole filter with triple-band performance has been designed and fabricated to verify this algorithm. Each of the three passbands has a fractional bandwidth of approximately 0.26%

Dual-band HTS filter using modified dual-spiral resonators

A symmetric dual-band filter with a centre frequency of 887 MHz is presented. The filter uses a modified structure of dual spiral resonators with interdigital capacitive load. At the same resonant frequency, the resonator can occupy an area of less than 2.75% of the area of the square loop resonator. Moreover, the resonator has a very low sensitivity to substrate thickness. The resonator structure also allows two types of couplings and, hence, allows application of cross-couplings with different signs to the direct couplings

Analysis and Design of E-shape Meander Line Antenna for LTE Mobile Communications

the meander line antenna (MLA) is an electrically small antenna. Electrically small antennas pose several performance related issues such as narrow bandwidth, low gain and high cross polarization levels. In this paper, we analysis and design an E-shape MLA as anew shape to achieve wider bandwidth and smaller gain at 2.5 GHz compared to the classical MLA. Parametric study has been done for the effect of changing each variable in the antenna structure and study the effect of this change on the antenna performance. The best` performance of separate variables is combined at the end which give suboptimal design. Professional design software (HFSS) is used to design and optimize the antenna and MATLAB codes were written to determine the resonant frequency and the bandwidth for each study in this paper

(7,4) Hamming-like Code for QPSK Modulation

Quadrature Phase Shift Keying (QPSK) is one of the most popular digital modulation techniques. It is widely used in existing technologies because of its spectral efficiency. In this paper, we present a (7, 4) code which can be directly applied on the phase of the QPSK constellation points. The code is based on the fundamental idea of the binary Hamming code. The decoding performance is enhanced by considering the minimum Euclidean distance between the received codeword and all codewords that that can be corrected using the same syndrome. The code can correct all the single symbol errors and 96.3% of double symbol errors at E b /N 0 = 8 dB. By simulation, it is shown that this approach can guarantee a coding gain of 1.5 dB with respect to uncoded QPSK. assigned to a unique syndrome. The correct codeword is chosen by considering the minimum Euclidean distance between the received codeword and every codeword that assigned to the same syndrome. This minimizes the number of searched sequences and hence reduces the ML decoding complexity. Moreover, it allows efficient use of soft-decoding approach on block codes whereas it is usually done in case of convolutional codes