No abstract

Physical control format indicator channel (PCFICH) carries the control information about the number of orthogonal frequency division multiplexing (OFDM) symbols used for transmission of control information in long term evolution-advanced (LTE-A) downlink system. In this paper, two novel low complexity receiver architectures are proposed to implement the maximum likelihood- (ML-) based algorithm which decodes the CFI value in field programmable gate array (FPGA) at user equipment (UE). The performance of the proposed architectures is analyzed in terms of the timing cycles, operational resource requirement, and resource complexity. In LTE-A, base station and UE have multiple antenna ports to provide transmit and receive diversities. The proposed architectures are implemented in Virtex-6 xc6vlx240tff1156-1 FPGA device for various antenna configurations at base station and UE. When multiple antenna ports are used at base station, transmit diversity is obtained by applying the concept of space frequency block code (SFBC). It is shown that the proposed architectures use minimum number of operational units in FPGA compared to the traditional direct method of implementation.

No abstract

Abstract-Mutual coupling is a critical issue in compact array design and reducing this is one of the main efforts in Microstrip antenna array design. Periodic structures can help in this situation by suppressing surface wave propagation in a given frequency range. The purpose of this work is to show the viability of using 2D EBG structures to this aim. This paper presents a double element Microstrip antenna array inserted with the EBG structures like conventional mushroom, Jerusalem cross slot and slot loaded EBGs around 5-6 GHz. The performances are compared for mutual coupling reduction. Simulated results verify the improvement in performance of the antenna array compared to the array antenna without EBG. The slot loaded EBG is found to be good showing a 5.8dB mutual coupling reduction. Index Terms-Electromagnetic bandgap (EBG) structures,microstrip antenna arrays, mutual coupling, surface wave. I. INTRODUCTIONMicrostrip antenna arrays have been popular for decades because they exhibit a low profile, small size, lightweight, low manufacturing cost, high efficiency, and an easy method of fabrication and installation. Furthermore, they are generally economical to produce since they are readily adaptable to hybrid and monolithic integrated circuits fabrication techniques at radio frequency (RF) and microwave frequencies however, significant degradation of performance happens due to mutual coupling between the antenna elements [1]. An antenna that is placed on a highpermittivity dielectric substrate may couple power into substrate modes. As substrate modes do not contribute to the primary radiation pattern, these modes are a loss mechanism which reduces as high as 60% of the radiated power and reduce the antenna efficiency.Various techniques are explicitly designed to suppress the surface wave. A straightforward way to reduce the mutual coupling of monopole antennas on high-impedance ground plane was developed in [2] In this paper, various EBG structures like conventional mushroom, Jerusalem cross slot and slot loaded EBGs are inserted between a two element microstrip line fed monopole antenna array to reduce the strong mutual coupling of coupled microstrip antennas. The performance and the mutual coupling are compared with and without the EBG structures with the Method of Moment simulations. II. EBG STRUCTURE CONFIGURATIONThe conventional mushroom like EBG structure was proposed in [3], [4]. It consists of four parts: a ground plane, a dielectric substrate, metallic patches and connecting vias as shown in Fig. 1(a). The operation mechanism of this EBG structure can be explained by an LC filter array which is shown in Fig. 1(b), the inductor L results from the current flowing through the vias, and the capacitor C due to the gap effect between the adjacent patches. For an EBG structure with patch width W, gap width g, substrate thickness h and dielectric constant ε r , the values of the inductor L and capacitor C are determined by the following formula: These formulas (1)- (4) are very simple and but their results...

Long Term Evolution (LTE) receiver processing involves decoding of complex valued received symbols from each antenna port to detect the codeword sent by the transmitter. The main objective of this paper is to design and implement the receiver hardware architectures for the control channels, PCFICH (Physical Control Format Indicator Channel) and PHICH (Physical Hybrid ARQ Indicator Channel) using fixed point and IEEE 754 single precision floating point arithmetic units for single input single output (SISO) configuration and validate their performance based on the signal to noise ratio (SNR) and mean square error (MSE) or the decision values for detecting the code words received. Floating point based receiver has an edge over fixed point in terms of reduced developing time, reduced complexity, higher accuracy, higher precision and tolerance to error but at the cost of increased hardware. Floating point based receivers employing folding and superscalar techniques to optimize the architectures through reduction in resource utilization are synthesized and implemented. ModelSim 6.4a is used to simulate the results while the architecture is implemented in Virtex-6 FPGA device using Xilinx-Plan Ahead tool.