26 research outputs found
Analysis of the Joint Viterbi Detector/Decoder (JVDD) Over a Coded AWGN/ISI System ss an LDPC Alternative
Using a lattice decorrelator in the Partitioned FBLMS algorithm
Proceedings of the International Conference on Information, Communications and Signal Processing, ICICS21208-12120027
Mechanisms of Minimum Skew Angle Actuation for Hard Disk Drives
The utilization of voice coil motor (VCM) rotary actuator in hard disk drives (HDDs) results in skew angles between the read/write head and disk rotation direction. The system performance and achievable capacity of hard disk drives are excessively sensitive to the skew angle [1–3]. The difference in skew angle, between the ID to the OD can be as large as more than 30 degrees in conventional 3.5” and 2.5” VCM actuated HDDs. This paper presents three mechanisms, namely, a slant arm/suspension mechanism, a guider track mechanism, and a 4 link mechanism which can be designed to achieve minimum skew angle actuations for hard disk drives. The slant arm/suspension mechanism reduces the skew angle to ± 2 degrees in rotary actuated systems. The guider track mechanism further achieves the skew angle as zero degree theoretically. As an approximation of the guider track mechanism, the 4 link actuation mechanism reduces the skew angle to 0.4 degree. Their system dynamic behaviors are studied numerically using finite element modelling. Some of designs are prototyped and experimentally investigated
Mechanisms of Minimum Skew Angle Actuation for Hard Disk Drives
The utilization of voice coil motor (VCM) rotary actuator in hard disk drives (HDDs) results in skew angles between the read/write head and disk rotation direction. The system performance and achievable capacity of hard disk drives are excessively sensitive to the skew angle [1–3]. The difference in skew angle, between the ID to the OD can be as large as more than 30 degrees in conventional 3.5” and 2.5” VCM actuated HDDs. This paper presents three mechanisms, namely, a slant arm/suspension mechanism, a guider track mechanism, and a 4 link mechanism which can be designed to achieve minimum skew angle actuations for hard disk drives. The slant arm/suspension mechanism reduces the skew angle to ± 2 degrees in rotary actuated systems. The guider track mechanism further achieves the skew angle as zero degree theoretically. As an approximation of the guider track mechanism, the 4 link actuation mechanism reduces the skew angle to 0.4 degree. Their system dynamic behaviors are studied numerically using finite element modelling. Some of designs are prototyped and experimentally investigated
Optimization of Dual-Structure Recording Media for Microwave-Assisted Magnetic Recording
Areal Density Capability of Dual-Structure Media for Microwave-Assisted Magnetic Recording
A general decoding framework for high-rate LDPC codes
This paper presents a hardware solution to the
design of general low-density parity-check (LDPC) decoders,
which simplifies the delivery network required by the message
passing algorithm. While many designs of LDPC decoders for
specific classes of codes exist in the literature, the design of a
general LDPC decoder capable of supporting random LDPC
codes is still challenging. The method proposed in this paper
tries to pack different check node (CN) and variable node (VN)
messages in the Tanner graph representation of the LDPC code,
and is therefore called message packing. This method takes
advantage of the fact that for high-rate LDPC’s the CN’s degree
is much larger than the VN’s, and two distinct methods for
delivering the messages to the CNs and VNs are proposed.
Using the proposed interconnection network (IN) results in lower
complexity decoding of LDPC codes when compared to other
designs.Published versio