Flexible LDPC Decoder Architectures

Flexible channel decoding is getting significance with the increase in number of wireless standards and modes within a standard. A flexible channel decoder is a solution providing interstandard and intrastandard support without change in hardware. However, the design of efficient implementation of flexible low-density parity-check (LDPC) code decoders satisfying area, speed, and power constraints is a challenging task and still requires considerable research effort. This paper provides an overview of state-of-the-art in the design of flexible LDPC decoders. The published solutions are evaluated at two levels of architectural design: the processing element (PE) and the interconnection structure. A qualitative and quantitative analysis of different design choices is carried out, and comparison is provided in terms of achieved flexibility, throughput, decoding efficiency, and area (power) consumptio

Coexistence Analysis between Radar and Cellular System in LoS Channel

Sharing spectrum with incumbents such as radar systems is an attractive solution for cellular operators in order to meet the ever growing bandwidth requirements and ease the spectrum crunch problem. In order to realize efficient spectrum sharing, interference mitigation techniques are required. In this letter we address techniques to mitigate MIMO radar interference at MIMO cellular base stations (BSs). We specifically look at the amount of power received at BSs when radar uses null space projection (NSP)-based interference mitigation method. NSP reduces the amount of projected power at targets that are in-close vicinity to BSs. We study this issue and show that this can be avoided if radar employs a larger transmit array. In addition, we compute the coherence time of channel between radar and BSs and show that the coherence time of channel is much larger than the pulse repetition interval of radars. Therefore, NSP-based interference mitigation techniques which depends on accurate channel state information (CSI) can be effective as the problem of CSI being outdated does not occur for most practical scenarios.Comment: Corrected some typos and reference

Electrochemical characterization of nanoporous nickel oxide thin films spray-deposited onto indium-doped tin oxide for solar conversion scopes

Nonstoichiometric nickel oxide (NiOx) has been deposited as thin film utilizing indium-doped tin oxide as transparent and electrically conductive substrate. Spray deposition of a suspension of nanoparticles in alcoholic medium allowed the preparation of uniform coatings. Sintering of the coatings was conducted at temperatures below 500°C for few minutes. This scalable procedure allowed the attainment of films with mesoporous morphology and reticulated structure. The electrochemical characterization showed that electrodes possess large surface area (about 1000 times larger than their geometrical area). Due to the openness of the morphology, the underlying conductive substrate can be contacted by the electrolyte and undergo redox processes within the potential range in which is electroactive. This requires careful control of the conditions of polarization in order to prevent the simultaneous occurrence of reduction/oxidation processes in both components of the multilayered electrode. The combination of the open structure with optical transparency and elevated electroactivity in organic electrolytes motivated us to analyze the potential of the spray-deposited films as semiconducting cathodes of dye-sensitized solar cells of p-type when erythrosine B was the sensitizer