Instruction set extensions for software defined radio on a multithreaded processor

Software dened radios, which provide a programmable solu-tion for implementing the physical layer processing of multi-ple communication standards, are widely recognized as one of the most important new technologies for wireless com-munication systems. Emerging communication standards, however, require tremendous processing capabilities to per-form high-bandwidth physical-layer processing in real time. In this paper, we present instruction set extensions for sev-eral important communication algorithms including convo-lutional encoding, Viterbi decoding, turbo decoding, and Reed-Solomon encoding and decoding. The performance bene ts of these extensions are evaluated using a supercom-puter class vectorizing compiler and the Sandblaster low-power multithreaded processor for software dened radio. The proposed instruction set extensions provide signicant performance improvements, while maintaining a high degree of programmability. Categories and Subject Descriptors C.3 [Computer Systems Organization]: Special-purpose and Application-based Systems|Real-time and embedded sys

Nonlinear high-temperature superconducting terahertz metamaterials

We report the observation of a nonlinear terahertz response of split-ring resonator arrays made of high-temperature superconducting films. Intensity-dependent transmission measurements indicate that the resonance strength decreases dramatically (i.e. transient bleaching) and the resonance frequency shifts as the intensity is increased. Pump–probe measurements confirm this behaviour and reveal dynamics on the few-picosecond timescale.Los Alamos National Laboratory. Laboratory Directed Research and Development ProgramUnited States. Office of Naval Research (Grant N00014-09-1-1103)National Science Foundation (U.S.) (American Competitiveness in Chemistry Fellowship 1041979

Assessing the Cost Effectiveness of LEED Certified Homes in Kentucky

The purpose of this study was to analyze the cost effectiveness of building new-construction single-family homes through the Leadership in Energy and Environmental Design (LEED) program in six counties of Kentucky. The estimated added LEED construction cost was calculated as well as its respective payback period based on the expected utility savings of LEED certification. A mortgage cost comparison was also performed comparing traditional code built to non-LEED single-family homes. Using descriptive statistical analysis on the simple payback period, mortgage costs were compared internally and by county. This study found that The LEED Certified and Silver level had payback periods less than 30 years, and the total 30 year net difference between non-LEED and LEED certified ranged from $-1,193.20 to$1,667.64

A Subword-Parallel Multiplication and Sum-of-Squares Unit

Several recent digital signal processors, multimedia processors, and general-purpose processors with multimedia extensions support subword parallelism. With subword parallelism, each operand is partitioned into multiple lowerprecision operands, called subwords. A single subwordparallel instruction performs the same operation on multiple sets of subwords in parallel. This paper presents the design of a subword-parallel multiplication and sum-ofsquares unit (SPMSSU). The SPMSSU uses novel subword partitioning and partial product mapping techniques to perform one 32-bit, two 16-bit, or four 8-bit multiplications or sum-of-squares operations in parallel. The SPMSSU efficiently performs subword-parallel operations with area and delay estimates that are comparable to those of a conventiona

Garbage Collection for the Delft-Java Processor

ABSTRACT. The Delft Java Processor (DJP) is a hardware approach aiming at accelerating bytecode execution. One of the critical tasks in a JVM that could benefit from hardware support is garbage collection. To efficiently perform garbage collection in the DJP we have to better understand the general garbage collection related issues in real life situations. In this respect we provide in this paper a study of the dynamic allocation behavior of Java programs based on the SPECjvm98 benchmark suite. Age, size and type distribution of Java objects are presented and interpreted from the general point of view of garbage collection, together with other garbage collection related measurements. Thus we can identify the features of an efficient DJP dedicated garbage collector and propose supporting architectural extension(s) in the DJP. The study confirms the weak generational hypothesis according to which objects are most likely to die very young, suggesting that a collector with two generations could improve garbage collection performance with corresponding hardware support. To fully take advantage of the generational hypothesis efficient hardware-implemented write barriers are needed. Hardware support is also recommended for describing the dynamic layout of the stack (stack pointer map) for accurate garbage collection