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In this paper, a low overhead preamble structure is proposed for the interference approximation method — complex (IAM-C) method in offset quadrature amplitude modulation based orthogonal frequency division multiplexing (OQAM-OFDM) systems. Compared with the conventional preamble structure with three columns of symbols, the proposed preamble structure only requires two columns of symbols as the preamble...
For massive MIMO systems, linear signal detectors, such as zero forcing (ZF) signal detector, can achieve the near-optimal performance, but usually involve high complexity due to the required matrix inversion of large size. In this paper, we propose a signal detector based on symmetric successive over-relaxation (SSOR) method without matrix inversion, which can reduce the complexity by one order of...
We study simulation of underwater communications using acoustic signals impaired by attenuation and multipath propagation. Attenuation is sensitive to the source-receiver separation distance, sound speed profile and signal frequency. Multipath propagation is affected by reflection and refraction due to the environment boundaries, sea surface and seabed, and sound speed profile. Simulation of attenuation...
Rapid development of Broadband Wireless Access (BWA) requires improvement of system capacity. MU-MIMO is considered as a benefit solution as its ability to enhance the system capacity without additional bandwidth. However, the implementation of MU-MIMO creates interference problem that is Multi User Interference (MUI). Thus in order to suppress the MUI, precoding technique is needed before the signal...
The bit error rate (BER) performance of CDMA system will rapidly deteriorate under the co-channel interferences. To solve the problem, we give a polyphase complete complementary sequence-based direct-sequence code-division multiple access (CC-DS-CDMA) for additive white Gaussian noise (AWGN) channel in this paper. Sets of sequences with complete complementary principle are known because of their ability...
Belief propagation (BP) algorithm has been widely used for decoding LT codes. It is well known that the premature termination of the BP decoding due to the lack of degree one symbols in the ripple impairs the decoding performance of the code. This problem has been well studied and tackled for binary erasure channel (BEC). However, for binary input additive white Gaussian noise (BIAWGN) channels, the...
In this paper, we propose a thresholding algorithm to improve Split-Row decoding method of irregular LDPC codes, with maintaining the same level of complexity. We present in this paper a full description of this method and its benefits for various row weight and length code word. In this context, we have performed an implementation on MATLAB of an irregular LDPC codes with different code word and...
In this paper, we show that the dimension of BS-MIMO system can be increased according to the extension of structure of the ESPAR antenna. For example, we show that it is possible to design the 7×7 BS-MIMO transmissions with the 13-element ESPAR antenna. MIMO dimension is expanded by one, when the number of parasitic elements of ESPAR antenna increases by two elements.
Orthogonal frequency division multiplexing (OFDM) is an attractive current technology for wireless communication systems due to its high spectral efficiency. One major disadvantage associated with OFDM is high peak to average power ratio (PAPR). It needs a large back-off high power amplifier (HPA) else degradation of bit error rate (BER) occurred. Selective mapping (SLM) is an effective technique...
As signal speeds continue to increase, maintaining signal quality has become a greater challenge for signal integrity (SI) engineers. Migrating a system to a next-generation interface technology operating at higher speeds brings with it increased sensitivity to attenuation and jitter that can severely curtail reach and reliability. In order to meet the interface specification, expensive choices such...
In this paper, we propose a novel additive cancellation signal (ACS) method for sidelobe suppression in non-contiguous orthogonal frequency division multiplexing (NC-OFDM) based CR systems. The key idea of the proposed method is to dynamically add several additive cancellation symbols on both the primary user (PU) subcarriers and the secondary user (SU) subcarriers, to generate the additive cancellation...
Non-binary quasi-cyclic (NB-QC) codes are a class of graph-based codes with high performance and implementation-friendly structure. In this paper, we introduce a new method for designing NB-QC codes with improved performance in the low error-rate region. Specifically, we propose a construction which reduces the number of non-binary absorbing sets, which are known to cause errors when decoding non-binary...
This article proposes an analysis of Smart Grid that has a communication protocol Power Line Communications (PLC) for low voltage networks, also called UM. A simulation by ns-2 is made to evaluate the performance of the network. Once the results of the simulation carried out an analysis of a resultant trace and fractional Brownian motion model which is a model that accommodates the emerging conditions...
In last few years, the IDMA scheme has attracted much attention of researchers around the world in the area of communication engineering. The researchers have demonstrated the capability of this scheme as a promising candidate for the fourth generation (4G) wireless communication systems. Presently, the scheme is finding its application not only in land area but also in acoustic communication. However,...
Effective algorithms in modern digital communication systems provide a fundamental basis for increasing the efficiency of the application networks. Equalizations are one of the preferred methods for increasing the efficiency of application systems such as OFDM. The step size is one of the main parameters of the equalization algorithms, because its value and its determining method change the convergence...
In this paper, we evaluate the outage probability and bit error rate (BER) performances of a three terminal full-duplex relaying (FDR) system with non-negligible residual self-interference (RSI). By investigating the signal-to-interference-plus-noise ratios (SINRs) at the relay and the destination respectively, the exact outage probability and BER of decode-and-forward (DF) based FDR system over Nakagami-m...
Underwater acoustic (UWA) communication attracts lots of attention due to its rapid development in maritime applications. In order to meet the increasing service requirements, multicarrier modulation techniques are desired for underwater communication implementations. In this paper, we study three types of multicarrier modulation schemes, e.g., the orthogonal frequency division multiplexing (OFDM),...
Channel shortening methods, in multicarrier systems, are applied for decreasing and almost compensating for the inter-symbol and inter-carrier interferences due to the channel delay spread. In this paper, we propose a new channel shortening technique for orthogonal frequency division multiplexing (OFDM) systems based. The propoed method is based on the neural network equipped with the Perceptron learning...
Low-Density Parity-Check (LDPC) codes with linear time encoding complexity and low hardware storage are a hot issue recently. We propose a general method for constructing LDPC codes with quasi-cyclic (QC) structure and improved zigzag pattern to obtain both linear time encoding and low hardware storage. We call it irregular repeat accumulate like (IRA-like) codes for its similarity with irregular...
The design of wireless embedded systems needs their efficient and realistic simulation to verify that requirements are met. The reproduction of communication behavior is crucial to assess the performance of hardware and software components, e.g., dependability and energy consumption. This work presents and discusses different levels of abstraction for the simulation of the communication behavior....
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