This report presents experimental results on a Multi-User MultiInput Multi-Output (MU-MIMO) channel of an antenna with orthogonal patterns and polarizations in an outdoor urban area. The antenna configuration employing orthogonal patterns and polarizations is useful in achieving a small terminal antenna since many antennas can be placed in the same location. The properties of this antenna are c...

Massive multiple-input multiple-output (MIMO) is a promising technology that provides high system capacity, and with excellent performance in energy efficiency and system robustness. However, pilot contamination restricts the system performance due to the limited length of orthogonal training sequences. In this paper, we propose optimization of nonorthogonal pilots for uplink training. The Gras...

As demand for high quality transmission increases increase of spectrum efficiency and an improvement of error performance in wireless communication systems are important . One of the promising approaches to 4G is adaptive OFDM (AOFDM) . Fixed modulation systems uses only one type of modulation scheme (or order), so that either performance or capacity should be compromised Adaptive modulated sys...

Using antenna arrays at both sides of the wireless communication link (MIMO systems) can result in high channel capacity provided that the channel is ideal, i.e., propagation medium is rich scattering or Rayleigh fading, the antenna arrays at both sides are uncorrelated. Also, the availability of channel side information (CSI) at the transmitter further enhances the capacity of ideal channels. ...

Shannon’s determination of the capacity of the linear Gaussian channel has posed a magnificent challenge to succeeding generations of researchers. This paper surveys how this challenge has been met during the past half century. Orthogonal minimumbandwidth modulation techniques and channel capacity are discussed. Binary coding techniques for low-signal-to-noise ratio (SNR) channels and nonbinary...

In critical energy infrastructure sectors (e.g. electric power generation, natural gas transportation, oil refining capacity) maintaining certain level of excess capacity is socially valuable (as it serves to protect against unexpected market conditions) but not necessarily compatible with the incentives for individual firms in the market. In this paper, we develop a dynamic oligopoly model wit...

This paper uses a previously developed spreadsheet cost model which simulates public transport modes operated on a 12km route to analyse the total costs of different passenger demand levels. The previous cost model was a very powerful tool to estimate the social and operator cost for different public transport technologies. However, as the model is strategic based, some assumptions are very bas...