Efficient frequency reusing schemes with multibeam satellite systems can be considered as a promising means of providing high-quality services expensive and limited bandwidth resources. This letter considers integrated terrestrial systems, where the same bands are reused in beams cells. In such condition, we propose an efficient power resource allocation scheme to minimize inter-component interference while maximum throughput is provided users. The proposed consists two simple linear machine...

Massive machine type communications or internet of things (IoT) over wireless systems have invoked attention in terms security problems, especially for multi-input multi-output (MIMO) schemes. In this paper, we propose efficient physical layer (PLS) enhancing methods space-time block coding (STBC), as well spatial multiplexing (SM) The proposed pre-distort the transmit signals by using phase information legitimate MIMO channel, and, a result, illegal eavesdropper cannot extract any...

This paper proposes high-speed computing decoders for polar codes based on a neural network. To compensate the performance gap with successive cancellation decoder, we propose applying recurrent network to BP decoder modified factor graph reduce computational complexity of without any degradation. The results simulation conducted in this reveal that proposed requires substantially less than conventional achieve same bit error rate performance.

Satellite systems can efficiently utilize expensive and limited bandwidth power resources, by reusing frequency bands over multibeams with provision of optimum resource allocation. This paper provides comparative analysis on the allocation schemes for multibeam satellite under interference-limited condition. After reviewing recent works machine learning-aided schemes, we propose a new idea to enhance performance. The performance estimation results investigated in this reveal that proposed...

Fast-polarization-hopping (FPH) transmission diversity is herein proposed to mitigate prolonged deep fades at the mobile receiver in, for example, indoor propagation environment. Even if individual multipaths are each sufficiently strong detection, may occur due multipath signals' destructive summation receiver. The relative immobility of transmitter, environment, and in environment means that a fade last very long duration, dropping calls or severing links. By rapidly hopping polarization...

Minimum mean squared error (MMSE)-based soft iterative detection schemes have been widely considered for coded multiple antenna systems due to their high performance gain with reasonable complexity. This letter presents compact universal equations estimate symbol values 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</sup> -ary QAM and PSK that can be applied any MMSE-based detection. The evaluation results investigated in this reveal the...

Soft symbol estimation (SSE) is the first process in soft interference cancellation minimum mean squared error (SIC-MMSE) detection for multiple-input multiple-output (MIMO) systems. SSE requires sum of exhaustive multiplications probability that occupies a non-negligible amount entire SIC-MMSE complexity. This paper proposes two approaches to reduce complexity SSE. The find approximation by investigating log-domain, which leads simple min-sum operation. second approximate hyperbolic tangent...

The polar code has become one of the most popular and important forward error correction (FEC) coding schemes due to its symmetric characteristics channel polarization. This paper reviews various decoding for codes discusses their advantages disadvantages. After reviewing existing performance-enhancing techniques such as belief propagation with list, a new method is proposed further improve performance. In addition, complexity reduction technique based on constituent proposed, scheduling...

Summary This paper introduces four proposals to enhance physical layer security (PLS) in low Earth orbit (LEO) satellite systems. The first proposal leverages the Alamouti code aided by artificial noise (AN) and involves collaborative use of two LEO satellites, ensuring secure downlink transmission. Its efficiency is further enhanced when implementing a power‐balanced code. second PLS capitalizes on an reconfigurable intelligent surface (RIS) introduce interference potential eavesdroppers....

In this paper, we propose a complexity reduced soft interference cancellation minimum mean squared error (SIC-MMSE) detection scheme for coded massive MIMO systems. The presented method works efficiently when the channel matrix becomes asymptotically orthogonal with sufficiently large number of receive antennas at base station. With such characteristic, conventional SIC-MMSE can be simplified to layer independent inversion process, and further reduction is achieved by introducing Neumann...

Abstract Due to advancements in modern mobile communication technology, massive numbers of devices are now connected the internet, but associated information also has be well protected. Many studies have proposed physical layer security (PLS) approaches utilizing artificial noise (AN), which is a simple approach protecting from an illegal receiver. However, this requires additional power allocation for AN. This paper proposes efficient balancing method Alamouti scheme, provides capability as...

Modern satellite systems utilize high frequency bands usually above 15 GHz to provide speed transmission services, and adopt adaptive modulation coding (AMC) schemes in order countermeasure serious rain fading occurred the utilized bands. This paper introduces an efficient scheme by using rateless codes. The proposed utilizes existing AMC with LDPC codes, thus it can be easily combined standards. error rate spectral efficiency performance simulation results demonstrate enhancement over a...

The satellite system is one of the most efficient means for broadcasting due to its wide service coverage as well fact that it can provide high data rate services by using frequency bands. However, there are a number problems in system, such long round trip delay (RTD) and heterogeneity channel conditions earth stations. Even though utilizing adaptive coding modulation (ACM) almost mandatory systems bands serious rain fading, RTD makes difficult quickly respond quality information, resulting...

This paper presents a computationally efficient soft detection scheme for massive multiple-input multiple-output (MIMO) systems. The proposed adopts joint iterative and decoding (JIDD) methods their capacity limiting performances. In addition, the minimum mean square error parallel interference cancellation (MMSE-PIC)-based is used information exchange. We propose number of techniques to reduce computational complexity, while keeping almost same performance as conventional ones. First,...

위성통신 시스템에서는 다중 빔을 이용한 동적 자원할당을 통해 주파수 자원을 효율적으로 활용할 수 있다. 재사용 기술을 빔 위성에 활용한 위성-지상 통합망은 이동 위성 서비스를 제공하기 위한 효과적인 수단이 될 이때, 동일한 대역을 재사용하는 빔과 지상 구성요소 간에는 상호 간섭이 발생할 있으며, 위성시스템의 매우 한정된 대역폭 및 전력의 효율적 활용을 위해서는 이러한 간섭환경을 고려하여 최적의 대역폭과 전력이 할당될 있도록 하여야 한다. 본 논문에서는 환경 하에서 동작할 있는 자원할당 방식의 기본 원리와 특징에 대해 소개한다. 또, 간 간섭을 모델링하고, 자원할당에 미치는 영향을 수식을 제시함으로써, 전력을 할당하는 알고리즘의 이론적인 해석이 제시될 더불어, 다양한 간섭 조건과 인자에 따라 성능을 광범위하게 시뮬레이션하고, 그 결과를 평가함으로써 실제 시스템 엔지니어링 과정에 활용될

Satellite systems serve as a crucial tool for non-terrestrial networks, offering solution to areas where terrestrial network coverage is limited. With the advanced capabilities of modern satellite that leverage frequency reuse across multiple beams, provision efficient 6G services becomes possible worldwide. However, achieving this efficiency requires an optimal resource allocation (RA) strategy considers interference-limited environment and constraints limited power bandwidth. This research...

본 논문에서는 수신안테나의 수가 송신 안테나의 수보다 더 많은 대용량 안테나 시스템에 효율적으로 적용할 수 있는 연판정 기반 반복 검출 기법을 제안하였다. 제안된 기법에서는 최소평균자승오류(minimum mean squared error; MMSE) 기반의 기법에서 가장 큰 연산량이 소요되는 복소 역행렬 연산을 뉴먼(Neumann) 무한급수 중 일부 중요 항을 채택함으로서 복잡도를 감소시킬 있도록 하였다. 이와 같은 복잡도 감소 기법이 부호화된 다중안테나 시스템에서 3개의 다중루프를 활용한 기법에 적용될 하였으며, 채널 특성을 활용하여 복잡도가 감소될 논문에서 제시된 시뮬레이션 결과를 통하여 기법은 기존의 비하여 훨씬 적은 수의 연산량을 가지고도 기존 근사하는 성능을 도출할 있음을 확인하였다.

본 논문에서는 무율부호를 이용하여 위성시스템에서의 강우 감쇠를 극복할 수 있는 효율적인 기법을 제안한다. 제안된 기법에서는 디지털위성방송표준의 하나인 DVB-S2(X)에 정의되어 LDPC 부호를 활용하여 설계한다. 부호어를 무율부호의 정보어로 간주하고, 부호기는 강우감쇠를 극복하기 위하여 두 가지 방법으로 패리티를 생성한다. 첫 번째 방법은 복호가 성공할 때까지 정해진 길이의 계속 재전송 하는 방법이고, 예측된 페이딩 값에 적절한 길이를 한번만 재전송하는 것이다. Ka 대역 위성강우감쇠 모델을 적용하여 시뮬레이션을 수행하고, 그 결과를 제시하여 논문에서 제시한 기법이 효과적으로 극복하는데 활용될 있음을 보인다.

Summary In this paper, we propose efficient parity allocation schemes when rateless codes are used in satellite communication systems conjunction with an adaptive coding and modulation (ACM) scheme. ACM widely modern to maintain the required error rate performance under channel impairment (such as rain fading observed high‐frequency bands). The enhancement of can be achieved by providing a good prediction mode method. case or error, effective means retransmission compensate for degradation....

Fast-polarization-hopping (FPH) transmission-diversity is herein proposed to mitigate prolonged deep-fades at the mobile receiver, e.g., in indoor propagation environment. Even if individual multipaths are each sufficiently strong for detection, deep fades may occur due destructive summation receiver. Relative immobility, communications' of transmitter and environment means any deep-fade last a very long duration, dropping calls or severing links. By fast-hopping transmission-polarization...