Radar micro-Doppler (m-D) signature, which reflects the micromotion dynamic and structural characteristics of radar target with micromotion, has received increasing attention. Most of the existing m-D signature-extraction methods operate in the time domain or the time-frequency domain. Different from these methods, in this paper, an m-D period estimation approach that operates in the ambiguity domain is proposed. Although the ambiguity function (AF) has been widely used in the field of radar signal processing, its application for m-D signal is introduced for the first time. It is proved that the AF of m-D signal exhibits periodicity along the lag axis and has the best concentration when the lag equals to multiples of the m-D period. Based on this, three AF concentration statistics are employed to capture the periodicity and to provide the m-D estimate. The most important property of the AF concentration statistics is that they are (or approximately) invariant to polynomial translations with terms not larger than second order even if the signal is Doppler ambiguous. Numeric simulation and real radar experiments are used to validate the effectiveness of the proposed technique. @en

To maximize the utilization of the available networks-on-chip (NoCs) link bandwidth, partially faulty links with low fault level should be utilized while heavily defected (HD) links should be deactivated and dealt with by means of a fault tolerant routing algorithm. To reach this target, we make the following contributions in this paper: 1) we propose a flit serialization (FS) method to efficiently utilize partially faulty links. The FS approach divides the links into a number of equal width sections, and serializes sections of adjacent flits to transmit them on all fault-free link sections to mitigate the unbalance between the flit size and the actual link bandwidth; 2) we propose the link augmentation with one redundant section as a low cost mechanism to mitigate the FS drawback that a link’s available bandwidth is reduced even if it contains only one faulty wire; and 3) we deactivate HD links when their fault level exceed a certain threshold to diminish congestion caused by HD links. The optimal threshold is derived by comparing the zero load packet transmission latency on the HD links and that on the shortest alternative path. Our proposal is evaluated with synthetic traffic and PARSEC benchmarks. Experimental results indicate that the FS method can achieve lower area*power/saturation_throughput value than all state of the art link fault tolerant strategies. With a redundant section in each link, the NoC saturation throughput can be largely improved than just utilizing FS, e.g., 18% when 10% of the NoC wires are broken. Simulation results we obtained at various wire broken rate configurations indicate that we achieve the highest saturation throughput if 4- or 8-section links with a flit transmission latency longer than four cycles are deactivated.@en