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Path loss models are the most fundamental part of wireless propagation channel models. Path loss is typically modelled as a (single-slope or multi-slope) power-law dependency on distance plus a log-normally distributed shadowing attenuation. Determination of the parameters of this model is usually done by fitting the model to results from measurements or ray tracing. The authors show that the typi
We have previously presented Intent, a medium access control scheme for WLANs based on cooperative, distributed, non-binding frame scheduling. The main idea behind Intent is intention sharing - a mechanism that allows a node to be aware of transmissions previously scheduled by its neighbors. We now extend this scheme to networks with hidden nodes. We give a formulation of the scheduling problem an
We present a general purpose algorithm for finding low-weight codewords as well as for decoding a received codeword in any quasi-cyclic code whose length and dimension is a multiple of a power of 2. In this paper, we apply the algorithm on a McEliece variant recently proposed by Misoczki et al. (MDPC-McEliece: New McEliece variants from moderate density parity-check codes, 2013). In their paper, t
Further exploitation of the spatial domain, as in Massive MIMO (MaMi) systems, is imperative to meet future communication requirements [1]. Up-scaling of conventional 4×4 small-scale MIMO implementations to MaMi is prohibitive in-terms of flexibility, as well as area and power cost. This work discloses a 1.1mm2 128×8 MaMi baseband chip, achieving up to 12dB array and 2× spatial multiplexing gains.
Massive MIMO is a promising technology for the coming 5G wireless systems. In this paper, a programmable baseband processor specifically designed for uplink symbol detection targeting massive MIMO is presented with a novel matrix inversion method proposed to obtain more precise and efficient computation. Including a microcode controlled channel preprocessing unit and a pipelined detection unit, th
This paper serves as an overview to the special session Circuits and Systems for 5G on IEEE International Conference on ASIC (ASICON) 2015. More specifically, we introduce two of enabling technologies for the coming 5G wireless era, namely massive multiple-input multiple-output (MIMO) technique and advanced coding techniques such as polar codes. Massive MIMO is a relatively new wireless communicat
The objective of this paper is to design a compressor for silicon debug that is suitable in an industrial Nexus environment. The compressor must operate in real-time and must be lossless. Important for the compressor is high compression ratio, low hardware cost and high throughput. We implemented the compression on an FPGA and we compared our implementation in terms of throughput and hardware cost
This paper presents a wideband quadrature radio receiver employing ΔΣ-based A/D-converting channel-select filters (ADCSFs). The output of the quadrature passive mixer is directly connected to the input of the ADCSFs, where a first-order ΔΣ modulator is incorporated into a fourth-order Butterworth channel-select filter (CSF) to provide sufficient dynamic range for a cellular system. A design method
One of the approaches to modify the McEliece cryptosystem to overcome its large key size is replacing binary Goppa codes with a new structured code. However, this modification makes such cryptosystems encounter some new attacks. There are a few modified McEliece cryptosystem variants which are known to be secure. One of them is the cryptosystem introduced by Baldi et al. which uses quasi-cyclic lo
Due to the increasing number of infotainment and safety functions in vehicles, the need for reliable communication link is becoming very critical. A key consideration in providing a reliable link is the antenna performance, which is conventionally evaluated by its efficiency and ability to provide the required coverage upon integration in vehicles. However, modern vehicles are equipped with many e
A microstrip antenna integration with a power amplifier is presented for the 60 GHz band. The antenna is a single layer 4×4 square patches array. The power amplifier is injection locked, designed in a 65 nm CMOS technology, with single-ended input and output signals. The integration is realized by means of bond wire connections. The antenna and the power amplifier are fabricated, characterized and
In the paper we address an important problem in minimum cost design of Elastic Optical Networks (EON), namely the problem of optimizing the configurations of Sliceable-Bandwidth Variable Transceivers (S-BVT) at the EON nodes. We first show how this optimization problem can be viewed and modeled as a combination of three bin-packing subproblems, with additional constraints ensuring feasibility of t
We present an optimization procedure that mixes advanced large-scale optimization methods and heuristics to solve large instances (with over 1.7 million integer variables) of the routing and spectrum allocation (RSA) problem - a basic optimization problem in flexgrid elastic optical networks. We formulate the problem as a mixed-integer program for which we develop a branch-and-price algorithm enha
The symmetric PMCHWT method of moments (MoM) impedance matrix allows for the characteristic modes (CMs) of a structure containing dielectric to be found. Recently, this impedance matrix was proven to provide non-real solutions which can be attributed to the MoM internal resonance problem. These internal resonances can be removed through different CM post-processing techniques. However, these studi
This work presents a broadband SiGe Power Amplifier (PA) for operation between 60-90 GHz covering both 71-76 GHz and 81-86 GHz E-Band sub-bands. It consists of a two-stage differential cascode amplifier using an LC-interstage matching network in the interface between the stages. Single-ended to differential conversion is accomplished by the use of two stacked 1-To-1 transformers, achieving a simul
In the paper we introduce an optimization framework for traffic restoration in optical wireless networks. As such networks experience multiple partial link failures, we introduce a generic extension of restoration strategies developed for wired networks (that assume total link failures) which enables handling partial link failures as well. The particular traffic restoration strategy studied in the
TO-DCF, a new backoff scheme for 802.11, has the potential to significantly increase throughput in dense wireless LANs while also opportunistically favouring nodes with heavier traffic loads and/or better channel conditions. In this paper we present an analytical model to investigate the behaviour and performance of the TO-DCF protocol with regards to operating parameters such as the number of nod
We present a high performance low-power digital base-band architecture, specially designed for an energy optimized duty-cycled wake-up receiver scheme. Based on a careful wake-up beacon design, a structured wake-up beacon detection technique leads to an architecture that compensates for the implementation loss of a low-power wake-up receiver front-end at low energy and area costs. Design parameter
This paper presents an adaptive QR decomposition (QRD) processor for five-band carrier aggregated LTE-Adownlinks. The design uses time and frequency correlationproperties of wireless channels to reduce QRD computationswhile maintaining an uncoded bit error rate loss below 1 dB.An analysis on the performance of a linear interpolating QRD ispresented and optimum distances for different channel condi
