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It has been proposed that six co-located antennas, namely three electric and three magnetic dipoles, can offer up to a six-fold capacity increase in wireless channels, relative to that of single antennas. In other words, six degrees of freedom (DOFs) can be supported by co-located six-port transmit and receive antenna arrays. However, due to the complexity in designing and measuring such a six-por
This paper presents a highly linear radio frequency receiver front-end with on-chip balun for cellular application at 2GHz in 65nm CMOS technology. Based on direct conversion architecture, the implemented front-end comprises a customized on-chip balun for single-ended to differential signal conversion, a differential common-gate low noise amplifier and voltage mode quadrature passive mixer. The si
Fully-synchronous measurements of a massive multi-user multiple-input multiple-output (MU-MIMO) radio propagation channel are presented. We evaluate the ability of a massive MIMO system to spatially separate users located close to each other in line-of-sight (LOS) propagation conditions. The system consists of a base-station (BS) antenna array equipped with 64 dual-polarized antenna elements (128
In this paper, we present a new topology to implement a passive 180° phase shifter using on-chip auto-transformer in an SOS process. The measured results indicate a phase variation of less than 2° over the frequency range of 1.8-2.4GHz. An insertion loss of 2.3dB was measured at 2.1GHz. The phase shifter has a small footprint of 0.3 × 0.7mm2, which is almost three times less than a traditional hig
Vehicle-to-Vehicle (V2V) communication is an en-abler for improved traffic safety and congestion control. As for any wireless system the ultimate performance limit is determined by the propagation channel. A particular point of interest is the shadowing effect of large vehicles such as trucks and buses, as this might affect the communication range significantly. In this paper we present measuremen
We give a procedure to find good convolutional codes for use with iterative decoding (turbo equalization) of the coded AWGN intersymbol interference (ISI) channel. The method is based on the input-output bit error rate characteristic of the convolutional BCJR module in the iterative decoder, in combination with the code minimum distance. Both are essential to find best codes. Best feedforward and
This paper presents a practical risk analysis method for critical, large-scale IT systems in an organisation. The method is based on reliability block diagram modelling and was adapted to fit the requirements of governmental organisations and to reduce the effort required to capture complex failure behaviour. Through the use of different failure categories the risk analysis can be simplified, the
In FSE 2010, Rønjom and Cid put forward a nonlinear equivalence for Boolean functions and demonstrated that many cryptographic properties are not invariant among functions within the same equivalence class by providing some special examples. Their paper presented the idea and many problems were left open.In this paper, we investigate equivalence of Boolean functions more deeply using a new method
The decoding problem is a fundamental problem in computational complexity theory. In particular, the efficiency of which the problem can be decided has implications on the security of cryptosystems based on hard problems in coding theory. Stern's algorithm has long been the best algorithm available, with slight modifications over the years yielding only small speed-ups. This paper describes an imp
A 5GHz digital frequency synthesizer achieving a low noise for wireless RF application is presented. This architecture uses a multi-delay coarse-fine Time-to-Digital Converter (TDC) to achieve both the large detection range and fine resolution. A Digitally Controlled Oscillator (DCO) based on capacitive degeneration in LC-Tank is also implement-ed. The DCO achieves frequency quantization step of 3
Consumers are pushing for higher data rates to support more services that are introduced in mobile applications. As an example, a few years ago video-on-demand was only accessed through landlines, but today wireless devices are frequently used to stream video. To support this, more flexible network solutions have merged in 4G, introducing new technical problems to the mobile terminal. New techniqu
In this paper, we introduce the concept of spatially coupled turbo codes (SC-TCs), as the turbo codes counterpart of spatially coupled low-density parity-check codes. We describe spatial coupling for both Berrou et al. and Benedetto et al. parallel and serially concatenated codes. For the binary erasure channel, we derive the exact density evolution (DE) equations of SC-TCs by using the method pro
