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Low power realization of high efficiency video coding (HEVC) standard, which has found widespread application in mobile devices, tablets, and high-definition televisions, calls for an efficient approximation of discrete cosine transform (DCT) technique. In this paper, a novel algorithm is proposed to determine the minimum number of low-frequency DCT coefficients required for transform and quantization block in HEVC. Moreover, it introduces hardware efficient 1-D architectures for 4, 8, 16, and 32-point DCT, that make use of the proposed algorithm and conform to the HEVC standard. When these architectures are extended to the HEVC test model (HM), it leads to a minor reduction of PSNR (<0.15 dB) and a slight increase in bitrate (<1.5%). The encoding time of HM encoder is reduced up to 16.02% and produces the rate-distortion performance comparable to the reference algorithm. A new memory efficient addressing scheme for transpose memory is presented for 2D-DCT. The proposed 2D-DCT architecture has a low power dissipation and energy consumption of 8.62 mW and 1.77 pJ respectively and can process at least sixty 8K ($7630\times 4830$) frames/s. Such architecture with low power and energy characteristics can be integrated into a real-time HEVC encoder for portable consumer electronic products. [ABSTRACT FROM AUTHOR]

Hardware search engines are widely used in network routers for high-speed look up and parallel data processing. Content addressable memory (CAM) is such an engine that performs high-speed search at the expense of large energy dissipation. Match-line (ML) power dissipation is one of the critical concerns in designing low-power CAM architectures. NOR-MLs make this issue more severe due to the higher number of short-circuit discharge paths during search. In this paper, an ML control scheme is presented that enables dynamic evaluation of a match-line by effectively activating or deactivating ML sections to improve the energy efficiency. $128{\boldsymbol \times }32$ -bit memory arrays have been designed using 45-nm CMOS technology and verified at different process-voltage-temperature and frequency variations to test the improvements of performance. A search frequency of 100 MHz under 1-V supply, at 27 °C applied on the proposed CAM results 48.25%, 52.55%, and 54.80% reduction in energy per search compared to a conventional CAM, an early predict and terminate ML precharge CAM (EPTP-CAM) and an ML selective charging scheme CAM, respectively. ML partition also minimizes precharge activities between subsequent searches to reduce total precharge power in the proposed scheme. An approximate reduction of 2.5 times from conventional and EPTP schemes is observed in the precharge dissipation. Besides low search power, proposed design improves the energy-delay by 42% to 88% from compared designs. [ABSTRACT FROM AUTHOR]

Unsharp masking is a popular image enhancement technique used to sharpen the image appearance in gray images. When applied to the color image, unsharp masking tends to introduce color distortion. In this paper, we propose a novel unsharp masking technique which can sharpen the image appearance without distorting the color and amplifying the noise. The proposed algorithm exploits the characteristics of the human visual system to control the level of sharpening and uses the energy dispersion filter to remove the color distortion. Experimental results show that our proposed algorithm successfully produces sharpened images that are free of noise and color distortion commonly found in conventional unsharp masking algorithm. [ABSTRACT FROM AUTHOR]

In this paper we provide a system design method to solve the problem of developing a miniaturized portable digital TV set. For such a portable device it is very important to reduce its power consumption and extend its operation time as its battery is the only power source in the system. The hardware circuitry, therefore, must be relatively compact to be in accord with the high integration of the system-on-chip (SOC) and the proper selection of key components. Not only miniaturization can be realized but also cost and power dissipation of the system can be decreased. Whether the implementation can be achieved also depends on antenna efficiency and DVB-T receiver performance. Therefore it is vital to select the right radio frequency architecture, which affects both the signal reception and the power consumption. Based on the demands mentioned above we have chosen single a conversion architecture for the receiver. Furthermore, our design has a better performance than earlier designs because of the use of a shielding case and the appropriate filtering of power ripples. We implement the built-in spiral antenna body by means of the printed circuit board which is low-cost, wideband, small-sized, low-profile, and omnidirectional. Moreover, a heat sink conducts the heat outward and prevents overheating, thus ensuring operational safety. [ABSTRACT FROM AUTHOR]

This paper presents a new skew control technique for a high speed mobile display serial interface. Unstable frequency and distorted duty ratio of recovered clock from the skew of data and strobe can be adjusted simultaneously by the proposed adaptive strobe delay controller (ASDC). Clock regulation is important because a raster image is re-constructed by using pixel clock from serialized host sending image data. By converting detected skews to voltage level and using a voltage controlled delay line (VCDL), the proposed adaptive skew control technique solves the problems of image distortion which are caused by several mismatched skew elements between data and exclusive OR (XOR) encoded strobe signal. The proposed skew controller and its related transceiver were implemented and also verified using a mega-pixel mobile image sensor. This technique has an output duty error of less than 3% under the instantaneous duty error of 20% and the implemented systems shows a good image quality from 500MHz to 1GHz normal operation with 3.5mW power dissipation. [ABSTRACT FROM PUBLISHER]

An adaptive Equalizer scheme is presented in OFDM system for IEEE 802.11a, g Wireless LAN. Conventional OFDM system employs a guard interval and a 1-tap Frequency-domain Equalizer (FEQ) to prevent delay spread distortions. This scheme is simple to implement, but provides low spectral efficiency due to the use of the guard interval. Moreover its performance is poor because of the lack of multipath diversity and the energy loss contained within the guard Interval. In the case where the Channel Impulse Response (CIR) is larger than the guard interval, the system performance is limited by the intersymbol and intercarrier interference. The proposed equalizer scheme consists of an adaptive Time-domain Equalizer (TEQ) and a 1-tap FEQ using long training OFDM symbols in the preambles. Its performance is better than that of the conventional OFDM system under severe delay spread and noise power conditions, especially in the case where the CIR is larger than the guard interval. This enables a reduction in the size of the guard interval and thus the spectral efficiency of the OFDM system can be improved. [ABSTRACT FROM AUTHOR]