A Scalable VLSI Architecture for Soft-Input Soft-Output Depth-First Sphere Decoding

Multiple-input multiple-output (MIMO) wireless transmission imposes huge challenges on the design of efficient hardware architectures for iterative receivers. A major challenge is soft-input soft-output (SISO) MIMO demapping, often approached by sphere decoding (SD). In this paper, we introduce the - to our best knowledge - first VLSI architecture for SISO SD applying a single tree-search approach. Compared with a soft-output-only base architecture similar to the one proposed by Studer et al. in IEEE J-SAC 2008, the architectural modifications for soft input still allow a one-node-per-cycle execution. For a 4x4 16-QAM system, the area increases by 57% and the operating frequency degrades by 34% only.Comment: Accepted for IEEE Transactions on Circuits and Systems II Express Briefs, May 2010. This draft from April 2010 will not be updated any more. Please refer to IEEE Xplore for the final version. *) The final publication will appear with the modified title "A Scalable VLSI Architecture for Soft-Input Soft-Output Single Tree-Search Sphere Decoding

A 2.78 mm2 65 nm CMOS Gigabit MIMO Iterative Detection and Decoding Receiver

Iterative detection and decoding (IDD), combined with spatial-multiplexing multiple-input multiple-output (MIMO) transmission, is a key technique to improve spectral efficiency in wireless communications. In this paper we present the—to the best of our knowledge—first complete silicon implementation of a MIMO IDD receiver. MIMO detection is performed by a multi-core sphere decoder supporting up to 4×4 as antenna configuration and 64-QAM modulation. A flexible low-density parity check decoder is used for forward error correction. The 65 nm CMOS ASIC has a core area of 2.78 mm2 . Its maximum throughput exceeds 1 Gbit/s, at less than 1 nJ/bit. The MIMO IDD ASIC enables more than 2 dB performance gains with respect to non-iterative receivers

Silicon implementation of iterative detection and decoding for multi-antenna receivers

Spatial multiplexing multiple-input multiple-output (MIMO) transmission schemes are increasingly used in wireless communication systems to cope with the growing data rate requirements and at the same time improve spectral efficiency, which quantifies how effectively the available bandwidth is exploited. MIMO techniques have a relevant impact on the complexity of the baseband signal processing algorithms, which typically hinders the implementation of a receiver with near-optimal communication performance. In particular, iterating over MIMO detection and channel decoding enables relevant performance gains but presents severe hardware implementation challenges, which are the main subject of this thesis and are addressed in two steps.First, the feasibility of max-log optimal soft-input soft-output MIMO detection is proven by implementing it in silicon. The corresponding design is based on a tree search-based algorithm known as sphere decoding (SD), whose complexity scales with the signal-to-noise ratio (SNR). This property is reflected by the hardware implementation, which shows high area and energy efficiency figures at high SNRs and is nevertheless able to attain max-log optimal communication performance at low SNRs, at a decreased efficiency. The prototype presented in this thesis is the first implementation of a 4x4 MIMO detector capable of max-log maximum a posteriori (MAP) performance reported in the literature.Based on this first achievement, the second step targets the realisation of an integrated iterative detection and decoding (IDD) baseband receiver. The design presented in this thesis includes five instances of the aforementioned SD-based MIMO detector. These instances are integrated in a multicore architecture that can process up to one MIMO symbol vector per cycle, thanks to an optimised data dispatching and collecting scheme and to a specialised memory architecture. An IEEE 802.11n compliant low-density parity check (LDPC) decoder subsequently performs channel decoding to correct the errors due to the noisy channel. According to the IDD principle, the detector and the decoder iteratively exchange information about the received bits to improve the decoding result. To enable this data exchange and achieve high throughput, a shared memory is designed which allows the two processing elements to work independently, in a pipeline-interleaved fashion, on two different sets of data. Several mechanisms are integrated in the receiver to reduce the computational burden by avoiding unnecessary computations that can occur in an iterative system. At a small implementation overhead, these techniques can significantly increase the efficiency of the MIMO IDD receiver.The design was fabricated as a 65 nm CMOS prototype, the first of its kind presented in the literature. Post-fabrication measurements show that the implementation, which has a core area of 2.78 mm2, can achieve throughput figures well above 1 Gigabit/sec with an energy consumption under 1 nJ/bit in good channel conditions. At the same time, it can approach max-log MAP optimal performance at low SNR, at an increased energy cost.This tradeoff between communication performance and area/energy efficiency is key in mobile wireless devices, which have to support high data rates while providing an acceptable battery lifetime. The implications of these conflicting goals are analysed extensively in the thesis, based on the post-fabrication measurements. Such an analysis shows how the many configurable parameters of the receiver (e.g., the runtime constraints on the detector and the decoder) and of the overall communication system (e.g., the modulation, the code rate, the number of MIMO streams) can be chosen to optimise a given target, such as spectral efficiency, data rate and energy efficiency. The choice of the parameter set can significantly change depending on the optimisation goal: for instance, energy efficiency benefits from using low modulation orders, due to the reduced detection complexity, in contrast with spectral efficiency, which increases with the modulation order.The reference implementation results of the MIMO IDD receiver prototype are also used to estimate with good reliability the area and energy costs for a max-log MAP receiver as a function of the bandwidth that it has to support. The outcome of this evaluation shows that near-optimal iterative detection and decoding is not only feasible but also profitably applicable to current mobile MIMO devices and communication standards. At a small impact on the battery lifetime, this technique improves the minimum operating SNR by 1 to 2 dB, depending on the modulation scheme and code rate

Sistema de Gestión de Seguridad de la Información y Riesgos de Información en seis sedes de una entidad bancaria del Perú.

Abstract In the present investigation, the risk levels of six agencies of a bank in Peru of the research period from september 2016 to september 2017, were analyzed and evaluated, as well as the proposal made on the implementation of the information security management system under ISO / IEC 27001: 2005 And the stages of the Deming (Plan-Do-Check-Act) model that can be applied, maintained and audited by the same entity, which guarantees that the objectives of the safety tool are achieved and benefit the company in the protection Of its assets, which will enable compliance with the rules in an efficient manner for the protection of assets. For this, the research methodology used was that of a descriptive design since we focused on the use of tables and statistical graphs for all the information collected in the users of the bank involved in the selected processes of the investigation. The research that has favorable results for the design since with the proposal of the security tool were found high risk levels (72% of risks in the study areas) that are the ideal ones to realize the implementation of the information security management system in the areas of Security, Banking users, IT, System and Helpdesk, noting in some cases that they do not have training in information security, with the findings obtained it was demonstrated to the High Direction that the analysis and evaluation of the risks should be mitigated or transferred to a third party, if necessary by establishing security polices. In the execution phase of the information security management system, High Direction must put a lot of emphasis so that the security tool can be maintained and monitored by security specialists in order to preserve the confidentiality, availability and integrity of the assets. These assets are within the proposal, as their purpose is to improve security in the selected processes of the bank as it was considered to be the most important processes in the bank, from which the proposal was made in 6 of its agencies And it was demonstrated that it is feasible the proposal to take actions on the implementation in the processes and that the bank is at the level that the other organizations are with this tool already implemented. Key words: Security policy, assets, availability, confidentiality, integrity, information risks.Resumen En la presente investigación se analizaron y se evaluaron los niveles del riesgo que cuentan seis sedes de una entidad bancaria del Perú en el periodo de investigación de setiembre del 2016 a setiembre del 2017, así como la propuesta realizada sobre la implementación del sistema de gestión de seguridad de la información bajo la norma ISO/IEC 27001:2005 y las etapas del modelo Deming (Plan-Do-Check-Act) y que pueda ser aplicado, mantenido y auditado por la misma entidad, el cual garantiza que se logren los objetivos de la herramienta de seguridad y beneficiar a la empresa en la protección de sus activos, el cual permitirá el cumplimiento de las normas de manera eficiente para la protección de los activos de información. Para lo cual, la metodología de investigación utilizada fue la de un diseño descriptivo puesto que nos enfocamos en el uso de cuadros y gráficos estadísticos por toda la información recopilada en los usuarios del banco intervinientes en los procesos seleccionados de la investigación. Investigación que cuenta con resultados favorables para el diseño puesto que con la propuesta de la herramienta de seguridad se encontraron niveles de riesgos medios y altos (72% de riesgos en las áreas de estudio) que son los ideales para realizar la implementación de un sistema de gestión de seguridad de la información en las áreas de Seguridad, Usuarios de banca, TI, Sistemas, Helpdesk, observando en algunos casos que no cuentan con capacitaciones en seguridad de información, con los hallazgos obtenidos se demostró a la Alta Gerencia que el análisis y la evaluación de los riesgos deben ser mitigados o transferidos a un tercero de ser el caso estableciendo políticas de seguridad. En la fase de ejecución del sistema de gestión de seguridad de la información la alta gerencia debe poner mucho énfasis para que la herramienta de seguridad pueda mantenerse y ser monitoreada por especialistas en seguridad con el fin de preservar la confidencialidad, disponibilidad e integridad de los activos. Estos activos se encuentran dentro de la propuesta, pues su fin es mejorar la seguridad en los procesos seleccionados de la entidad bancaria ya que se consideró que son los procesos más importantes en la entidad bancaria, del cual se realizó la propuesta en 6 de sus sedes principales y se demostró que es factible la propuesta para tomar acciones sobre la implementación en los procesos y que la entidad bancaria esté al nivel que las demás organizaciones se encuentran con esta herramienta ya implementada. Palabras clave: Sistema de gestión de seguridad de la información, política de seguridad, activos, disponibilidad, confidencialidad, integridad, riesgos de información