Transceiver design for non-regenerative MIMO relay systems with decision feedback detection

In this paper we consider the design of zero forcing (ZF) and minimum mean square error (MMSE) transceivers for non-regenerative multiple input multiple output (MIMO) relay networks. Our designs utilise linear processors at each stage of the network along with a decision feedback detection device at the receiver. Under the assumption of full channel state information (CSI) across the entire link the processors are jointly optimised to minimise the system arithmetic mean square error (MSE) whilst meeting average power constraints at both the source and the relay terminals. We compare the presented methods to linear designs available in the literature and show the advantages of the proposed transceivers through simulation results

ZF DFE transceiver design for MIMO relay systems with direct source-destination link

In this paper we consider a non-linear transceiver design for non-regenerative multiple-input multiple-output (MIMO) relay networks where a direct link exists between the source and destination. Our system utilises linear processors at the source and relay as well as a zero-forcing (ZF) decision feedback equaliser (DFE) at the receiver. Under the assumption that full channel state information (CSI) is available the precoding and equaliser matrices are designed to minimise the arithmetic mean square error (MSE) whilst meeting transmit power constraints at the source and destination. The source, relay, and destination processors are provided in closed form solution. In the absence of the direct link our design particularises to a previous ZF DFE solution and as such can be viewed as a generalisation of an existing work. We demonstrate the effectiveness of the proposed solution through simulation and show that it outperforms existing techniques in terms of bit error ratio (BER)

Robust transceiver design for MIMO relay systems with tomlinson harashima precoding

In this paper we consider a robust transceiver design for two hop non-regenerative multiple-input multiple-output (MIMO) relay networks with imperfect channel state information (CSI). The transceiver consists of Tomlinson Harashima Pre-coding (THP) at the source with a linear precoder at the relay and linear equalisation at the destination. Under the assumption that each node in the network can acquire statistical knowledge of the channel in the form of a channel mean and estimation error covariance, we optimise the processors to minimise the expected arithmetic mean square error (MSE) subject to transmission power constraints at the source and relay. Simulation results demonstrate the robustness of the proposed transceiver design to channel estimation errors

Tomlinson Harashima precoding design for non-regenerative MIMO relay networks

In this paper we consider the design of minimum mean square error (MMSE) transceivers for non-regenerative multiple input multiple output (MIMO) relay systems. Our design utilises Tomlinson Harashima precoding (THP) at the source along with linear processors in each stage of the network. Assuming full channel state information (CSI) is available at each node in the network the various processors are jointly optimised to minimise the system arithmetic mean square error (MSE) whilst abiding by average power constraints at both the source and relay terminals in the network. Simulations show that the proposed schemes outperform existing methods in terms of bit error ratio (BER)

Identifying Temporal Sensitivity of Poinsettia Flowering to High Temperatures

High temperatures can cause delayed flowering in poinsettia (Euphorbia pulcherrima Willd. ex Klotzsch), a phenomenon known in the industry as heat delay. The poinsettia wholesale market is concentrated to a relatively brief period from early-November through early-December putting growers at risk to heat delay. This problem is compounded by the unusual weather patterns created by climate change. The objective of this thesis was to identify periods in which poinsettia flowering is sensitive to high temperatures. First, the weeks within the growing season when the plants were sensitive to high temperatures were identified (Chpt. 2). Then within those sensitive weeks, the hours within a 24-h cycle when the plants were most sensitive were identified (Chpt. 3). In Chapter 2, two experiments were conducted; one experiment was conducted in greenhouses under natural daylength (ND) conditions while the other was conducted in growth chambers with LED lighting that initially provided a 11 h 01 min night length (NL) that increased by 2 min each day to simulate ND conditions in September and October at 34°N.Lat. One group of plants was moved each week from a moderate-temperature environment (22 °C average daily temperature [ADT]) to a high-temperature environment (28 °C ADT); plants spent one week in the high-temperature environment before returning to the moderate-temperature environment and being replaced by the next weekly treatment group. This treatment period lasted for 7 or 8 weeks for the growth chamber and greenhouse studies, respectively, after which plants were finished in a 22 °C ADT greenhouse. An additional group of plants was kept in either the moderate- or high-temperature environment for the entire treatment period to serve as controls. Four cultivars were grown in the greenhouse experiment: Advent Red, Freedom Red, Prestige Red and Tikal Red, while only Prestige Red was grown in the growth chamber experiment. Advent Red was identified as the most heat tolerant cultivar followed by Tikal Red, Freedom Red and Prestige Red. Periods of sensitivity to high temperatures for Advent Red, Tikal Red, Freedom Red and Prestige Red were 4-Sept. to 1-Oct., 11-Sept. to 8-Oct., 11-Sept. to 22-Oct. and 4-Sept. to 29-Oct., respectively. From the growth chamber study, a period of temperature sensitivity was identified when night lengths were between 11 h 01 and 12 h 37. Within these periods of sensitivity to high temperature, time to visible bud and anthesis were most affected by high temperatures in earlier weeks while final bract color development and time to first color were more affected by high temperatures during the latter weeks. Across both experiments, Freedom Red, Tikal Red and Prestige Red experienced delays to anthesis \u3e1 d per day of high-temperature treatment suggesting a residual impact of high temperatures. In Chapter 3, over 2 weeks Prestige Red plants were exposed to high-temperature treatments of 28 °C during four periods of a 24-h cycle (12-h night/ 12-h day): the first 6 h of the day, last 6 h of the day, the first 6 h of the night, or the last 6 h of the night. Additionally, plants were exposed to the high-temperature treatment during the entire 12-h night or 12-h day period within a 24-h cycle as well as a moderate- and high-temperature control for a duration of 2-weeks. Following the treatment period, all plants were moved to a glass greenhouse to finish flowering in moderate temperatures (22 °C ADT) under a 12-h NL. High-temperature treatments applied during the last 6 h of the night, the entire 12 h of the night and the entire 24-h period caused the most significant flowering delays. There were no significant differences between these treatments indicating that these delays were primarily due to high temperatures during the last 6 h of the night. High-temperature treatments applied during the first 6 h of the day and entire 12 h of the day were significantly less impactful. For most floral responses, there was no significant difference between these two treatments indicating that delays in the 12-h-day treatment were primarily caused by high temperatures during the first 6 h of the day. High-temperature treatments applied during the first 6 h of the night and last 6 h of the day resulted in comparatively minor flowering delay

Introduction

Introduction to Kōtare 2008, Special Issue — Essays in New Zealand Literary Biography Series Two: ‘Early Male Prose Writers

Welcoming the stranger: An exploration of the nature of the work of Mennonite Christians in the work of refugee assistance in the region of Waterloo

Mennonite Christians in the Kitchener Waterloo region have been involved in the work of refugee assistance for the past 25 years as an expression of their Christian faith. Their involvement is primarily in two forms. One form of refugee assistance is through providing sponsorship to refugees from overseas to Canada. Sponsorship is done through the Mennonite Central Committee of Ontario and Federal Private Sponsorship Program. In this program, Church congregations commit themselves to the financial and settlement support of the sponsored refugee(s) for a minimum of one year. The other form of assistance is through the funding and staffing of the Mennonite Coalition for Refugee Support (MCRS), a small agency in downtown Kitchener that provides settlement support to refugee claimants as well as assistance on the refugee claim process. This qualitative study explored the work of refugee assistance undertaken by Mennonite Christians in the Kitchener Waterloo region through their engagement in private sponsorship and with MCRS. Twelve individuals participated in the research through engagement in qualitative, semi-structured interviews. Data from the interviews was analyzed and four themes emerged that help to describe the nature of the work of refugee assistance. Although many themes emerged from the research, it was found that overarching each of these is the greater theme of “Welcoming the Stranger” which describes the desire of Mennonite Christians to adhere to the Biblical call to play host to those who are marginalized within society