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Based on the current development direction of frequency source and its application field, the advantages and difficulties in realization of dual-band frequency source are analyzed in this paper. A dual-band DDS system of digital receiver is chosen as an analytic object. The causes and mechanisms of the crosstalk problem are demonstrated, and a general method for crosstalk optimization is proposed...
A new method for passive detection problem with multi-static radar system is proposed. The direct-path signals in the surveillance channels are retained in the signal model. Utilizing both the reference signals and surveillance signals to obtain more accurate estimate for the illuminator of opportunity (IO) signals successively, a generalized likelihood ratio test (GLRT) detector is derived. Due to...
There are some challenges associated with the spectrum sensing for cognitive radio (CR), one main challenge of spectrum sensing is hardware requirements. The paper proposes the energy detection and a direct-conversion spectrum sensing receiver (DCSSR) to respond to the challenge of hardware requirements. However, the main problem is DC offsets of the DCSSR. A DC offset adaptive energy detection (DC-AED)...
The study of the paper concerns with the timing and synchronization problems in the impulse radio-ultra wideband (IR-UWB) positioning system. A novel synchronization algorithm based on two-stage enveloping method to improve the conventional sliding correlation performance is proposed. The correlator output is processed by two-stage enveloping firstly, then the fine synchronization interval is determined...
Adaptive video transmission schemes are important for real-time video services in wireless networks due to dynamic and volatile wireless environment. Traditional adaptation schemes always take network status of the sender or perceived quality of receiver into consideration, which are rather significant for end-to-end video transmission. This paper proposes a novel Quality of Experience (QoE) based...
There are two common spectrum sharing modes for cognitive radio (CR) networks: underlay and overlay. By a combination them, we propose here the hybrid spectrum sharing (HSS) model, where the transmission power is changed according to the states of the occupied sub carrier and interference constraints and thus, cognitive users can dynamically handoff between the overlay mode and the underlay mode....
The performance of transmit antenna selection is investigated. The exact closed-form expressions for the average BER and average SNR in MRT systems and EGT systems are proposed. The minimum number of increased transmit antennas sufficient to compensate the performance loss for using part of transmit antennas is analyzed. The validity of the performance analysis is demonstrated by computer simulation.
By borrowing ideas from a cryptographic algorithm of low key authentic degree, a novel steganographic method based on keyword shift is presented. The master key of the method is to shift the sensitive keywords in the text. The conditions to guarantee the reversibility of the method are analyzed and found out, the serviceability of the method in some situations is pointed out. The strong points and...
Robustness enhancement scheme in Serial RapidIO (SRIO) interconnect is proposed to overcome the performance degradation caused by noise and Electromagnetic Interference (EMI). The main idea of this scheme is the adaptive speed transition and mode conversion. Adaptive speed transition can improve average throughput and reduce delay in high Bit Error Rate (BER) environment. Mode conversion is to conquer...
High-definition multimedia interface (HDMI1.3) specifies video serial link that operates from as low as 250 Mb/s to 3.4 Gb/s with coverage over different multimedia data formats. Wide-spread consumer adoption of the new HDMI standard demands receivers that reliably reproduce the incoming data stream under conditions of either short/long cables or clear/fuzzy signal. In many cases, input video signal...
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