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Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) is an integral part of Orthogonal Frequency division multiplexing (OFDM) systems. This forms the physical layer architecture of wireless systems and is designed to consume low power. This paper presents a low power and area efficient architecture for the FFT implementation. FFT involves more complex addition and multiplication...
Extensive deployment of heterogeneous small cells over existing macrocell cellular networks forms the Ultra-dense Small cell Network (USN). USN has emerged as a key networking architecture in 5G wireless networks. It can improve network coverage and boost system capacity. However, the dense overlapped deployment of small cells leads to a complex interference problem. In this paper, we jointly implement...
In this paper, a novel design of Multi-Path Delay Commutator Architecture FFT processor(MDC-FFT) is proposed based on customized rotation factor ROM(RF-ROM) with various memory access mechanism for OFDM systems. For the OFDM systems, the combined FFT algorithm of Radix-2 FFT and Radix-22FFT is conducted. The pipeline architecture is also proposed for its high throughput and scalability. With hybrid...
Inter-Cell Interference (ICI) is always a key problem in Fractional Frequency Reuse (FFR) system to be focused on, which should be well resolved to pursue higher throughput and better power efficiency. In this paper, we investigate throughput and power efficiency of RR scheduling in FFR system by both closed-form expression and Monte Carlo trials method. We improve a previous throughput model by applying...
This paper presents a shared canonical signed digit (CSD) complex constant multiplier for high-speed low-complexity parallel fast Fourier transform (FFT) processors. To reduce the number of twiddle factor (TF) multiplications, the mixed radix −24/23 FFT algorithm is adopted for FFT processor. The 512-point FFT processor using the proposed shared CSD complex constant multiplier has been designed and...
Mobile Radio Communications Systems have retained engineers' attention, research and commerce communities long time ago. In order to certify both Signal Processing and Radio Communications discipline developments, novel systems design are continuously introduced. This is obtained after long, correct and accurate test procedures which begin over multiple tests usually done over a simulation procedure...
The combination of multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) is a promising solution for high-data-rate transmission. An architecture of a K-best based list sphere detector (LSD) algorithm for a MIMO-OFDM system is introduced in this paper. The architecture was designed for a 2 × 2 antenna system with quadrature phase shift keying (QPSK) and 16-quadrature...
With growing demand of machine to machine (M2M) communication, wireless communication systems request simultaneous connections for many terminals to cope with thus increasing communication throughput. We focus on interleave division multiple access (EDMA) that has superior user detection performance and describe a VLSI design of an interference canceller that performs user detection in QPSK OFDM-IDMA...
This paper presents a multi-path delay commutator (MDC) FFT processor for high-speed. The proposed FFT processor can achieve a high throughput by using a parallel datapath scheme and a multi-path delay commutator structure. The proposed processor can provide a low hardware complexity and an efficient scheduling scheme of complex multiplications. The proposed efficient scheduling scheme can reduce...
Device-to-Device communication allows two cellular devices to communicate with each other without a base station. By relieving the base station from relaying data to and from different devices, D2D communication aims at increasing the system capacity. In a D2D enabled network, one of the critical issues is to effectively allocate frequency resource. In this paper, a resource allocation scheme has...
In this paper we present an architecture for an MMSE filter matrix computation unit for signal detection in MIMO-OFDM communication systems. We propose to compute the required matrix inverse based on a Cholesky decomposition, followed by a Gauss-Jordan matrix inversion of the resulting triangular matrix. The high dynamic range required by this approach is traditionally conquered with custom floating-point...
Inter-cell interference (ICI) is always a big issue in orthogonal frequency division multiple access (OFDMA) based communication networks. In this paper, we apply power control to an Improved Fractional Frequency Reuse (IFFR) scheme and investigate the system performance. IFFR scheme divides the whole available resources into two segments: the first segment and the second segment. The first segment...
In this paper we propose a fully parallel 64K point radix-44 FFT processor. The radix-44 parallel unrolled architecture uses a novel radix-4 butterfly unit which takes all four inputs in parallel and can selectively produce one out of the four outputs. The radix-44 block can take all 256 inputs in parallel and can use the select control signals to generate one out of the 256 outputs. The resultant...
In this paper, we propose an enhanced eight-parallel 128/256-point mixed-radix multi-path delay commutator (MRMDC) FFT/IFFT processor for high-speed orthogonal frequency-division multiplexing (OFDM) systems to reduce the number of complex multipliers. The proposed processor can achieve a high throughput rate by using an eight-parallel data-path scheme and an efficient scheduling scheme of complex...
In cellular systems, Fractional Frequency Reuse (FFR) partitions each cell into two regions; inner region and outer region and allocates different frequency band to each region. Since the users at the inner region are less exposed to inter-cell interference, the frequency resources in each inner region can be universally used. Based on this frequency band allocation, FFR may reduce channel interference...
The evolution of 60 GHz wireless networks using Orthogonal Frequency Division Multiplexing (OFDM) technique imposed requirements of increased processing in the baseband implementations. The current paper focuses on the design of a pipelined architecture realizing the baseband functions. The design bases on using parallel paths to achieve a throughput of 1.6 Gbps. The number of paths is configured...
Radio spectrum resources are becoming scarce with the increasing demand for multiple users wireless services. Hence, it is an important problem to increase the system potential capacity and coverage for wireless system in future. This paper aims at proposing a relay algorithm based on power control and SINR evaluation for two-hop OFDM cellular networks with fixed relay stations. This algorithm improves...
Interference management is always a challenge issue in OFDMA system. In this paper, an enhanced fractional frequency reuse (EFFR) architecture based on interference avoidance scheme coupled with power control is proposed to solve the problem of interference management in multi-cell OFDMA environment. The scheme divides whole sub-carriers into several groups orthogonally. The groups are assigned to...
This paper presents a novel eight-parallel 128/256-point mixed-radix multi-path delay commutator (MRMDC) FFT processor for orthogonal frequency-division multiplexing (OFDM) systems. The proposed FFT architecture can provide a higher throughput rate and low hardware complexity by using an eight-parallel data-path scheme, a multi-path delay commutator structure and an efficient scheduling scheme of...
In this paper a new method for uplink inter-cell interference coordination (ICIC) in a full frequency reuse system is proposed. The technique is named uplink interference protection (ULIP). ULIP exploits existing reference signals transmitted by all base stations (BSs). The fact that path loss and lognormal shadowing can be considered reciprocal in such frequency-division duplex (FDD) systems is exploited...
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