Sharif Digital Repository

A novel architecture for QR decomposition-based recursive least squares is presented. It offers low latency for applications where the channel equalization and adaptive filtering are mandatory. This approach reduces the computations by rewriting the equations in a manner that lets intense hardware resource sharing by reusing similar values in different computations. Moreover, precision range conversion allows for combining complex operations such as root square and division with minimum effect on the overall quantization error. Hence, an efficient lookup table-based solution has highly enhanced the performance of the design by 2.7 times with respect to the previous works  

A Digital Delta Sigma Modulator (DDSM) is a Finite State Machine (FSM); it is implemented using finite precision arithmetic units and the number of available states is finite. The DDSM always produces a periodic output signal when the input is constant. This paper proposes a novel method of applying periodic dither to a DDSM in order to obtain minimized spurious tones. The effects of adding the pseudorandom dither signal in different stages within the proposed Multi-Stage noise Shaping (MASH) modulator are expressed in the equations, and the results are compared. We present results regarding the periodicity of the quantization noise produced by a MASH modulator with a constant input and a... 

The amount of high dimensional data produced by visual sensors in the smart environments and by autonomous vehicles is increasing exponentially. In order to search and model this data for real-time applications, the dimensionality of the data should be reduced. In this paper, a novel dimensionality reduction algorithm based on fuzzy rough set theory, called Centralized Binary Mapping (CBM), is proposed. The fuzzy CBM kernel is used for extracting the central elements and the memory cells from the blocks of high dimensional data. The proposed applications of CBM in this paper include hashing and generative modelling of multimedia big data. The robustness of the proposed CBM based hashing... 

This paper presents a new architecture for a DLL based frequency synthesizer. Occupying low area, lower power consumption and phase noise are the advantages of this novel architecture. DLLs are first ordered systems, so good stability can be obtained in this design. This structure also can be used for generating fractional multiple of reference frequencies. The proposed circuit can operate at a substantially low supply voltage. A case in point, the synthesizer is adopted to create the channel frequencies of French DVB-H/T standard. The circuit is designed based on 0.13um CMOS Technology. Also power consumption trade-offs are introduced. It was shown that 27 delay cells are sufficient to... 

We propose a new optical reconfigurable Network-on-Chip (NoC), named ReFaT ONoC (Reconfigurable Flat and Tree Optical NoC). ReFaT is a dynamically reconfigurable architecture, which customizes the topology and routing paths based on the application characteristics. ReFaT, as an all-optical NoC, routes optical packets based on their wavelengths. For this purpose, we propose a novel architecture for the optical switch, which eliminates the need for optical resource reservation, and thus avoids the corresponding latency and area overheads. As a key idea for dynamic reconfiguration, each application is mapped to a specific set of wavelengths and utilizes its dedicated routing algorithm. We... 

Novel architecture of high precision localization using optical flow sensor (OFS) combined with Iterative Point Tracking Algorithm (IPTA) is proposed. This work focuses on attenuation of OFS' sensitivity dependency on texture of surface over which sensor is moving. The aim for the design of experimental setup is to verify how much a robustness of OFS's sensitivity on various surfaces improves. In this regard, four different surfaces' texture including iron, paper, textile and granite stone is opted. Experimental results indicate that sensor's resolution via IPTA on surfaces of iron, paper, textile and granite stone respectively equal to 382, 460, 528 and 448 CPI. Optimal value of the... 

This article presents a new QoS architecture for IEEE 802.16 Broadband Wireless MAN. The newly proposed strategy of providing QoS in packet-based networks via IEEE 802.16 has been analyzed. A mapping rule for providing layer 2.5 (MPLS protocol) and MAC layer has been proposed. A fast signaling mechanism has been designed to provide QoS in Point to Multipoint (PMP) mode. Although IEEE 802.16 standards define different mechanisms to provide Quality of Service requirements, it is the responsibility of the developers to obtain efficient designs. In this paper, we introduce a novel architecture for providing QoS requirements such as bandwidth utilization and delay. Simulation result shows the...