Master of Science

thesisFilter Bank Multicarrier (FB-MC) is a technique similar to Orthogonal Frequency Division Multiplexing (OFDM), used to divide the spectrum of a transceiver into multiple subcarriers or channels. When a single symbol is repeated across all subcarriers, its energy is spread across the entire spectrum. This is referred to as Filter Bank Multicarrier Spread Spectrum (FB-MC-SS). The design of a preamble or training sequence used in the packet construction of a FB-MC-SS transceiver system is explored in this thesis. The preamble is used to acquire an estimate of the channel impulse response and noise variance for each subcarrier. This information is then used to undo the effect of the channel and perform Maximum Ratio Combining (MRC) across all subcarriers. An alternating {+1, âˆ'1} sequence has been previously proposed for its implementation simplicity. An alternating {+1,âˆ'1} sequence leads to detection advantages as a result of the impulse response of the matched filter. An alternating {+1,âˆ'1} sequence also presents many disadvantages. Mainly, the sequence is susceptible to interference because of its distinct frequency. The alternating {+1, âˆ'1} sequence also has a higher probability of detection by unauthorized users. To combat these deficiencies of the alternating {+1,âˆ'1} sequence, pseudorandom sequences are explored in this thesis. The goal of the pseudorandom sequence is to gain ro- bustness without forfeiting the packet’s detectability by intended receivers. Pseudorandom Polyphase and Maximum Length Binary sequences are explored as randomized preambles. Both the alternating {+1, âˆ'1} sequence and the pseudorandom sequence are implemented separately in the FB-MC-SS transceiver on a Xilinx FPGA to compare resource utilizations. Pseudorandom Polyphase preamble sequences lead to robust channel frequency response and noise variance estimation in interfered environments. Although alternating {+1, âˆ'1} sequence leads to straightforward packet detection and simple FPGA implementation, the susceptibility of an alternating {+1, âˆ'1} preamble to interference makes a pseudorandom preamble sequence more desirable

Multihospital Outbreak of a Middle East Respiratory Syndrome Coronavirus Deletion Variant, Jordan: A Molecular, Serologic, and Epidemiologic Investigation

Background An outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV) in Jordan in 2015 involved a variant virus that acquired distinctive deletions in the accessory open reading frames. We conducted a molecular and seroepidemiologic investigation to describe the deletion variant’s transmission patterns and epidemiology. Methods We reviewed epidemiologic and medical chart data and analyzed viral genome sequences from respiratory specimens of MERS-CoV cases. In early 2016, sera and standardized interviews were obtained from MERS-CoV cases and their contacts. Sera were evaluated by nucleocapsid and spike protein enzyme immunoassays and microneutralization. Results Among 16 cases, 11 (69%) had health care exposure and 5 (31%) were relatives of a known case; 13 (81%) were symptomatic, and 7 (44%) died. Genome sequencing of MERS-CoV from 13 cases revealed 3 transmissible deletions associated with clinical illness during the outbreak. Deletion variant sequences were epidemiologically clustered and linked to a common transmission chain. Interviews and sera were collected from 2 surviving cases, 23 household contacts, and 278 health care contacts; 1 (50%) case, 2 (9%) household contacts, and 3 (1%) health care contacts tested seropositive. Conclusions The MERS-CoV deletion variants retained human-to-human transmissibility and caused clinical illness in infected persons despite accumulated mutations. Serology suggested limited transmission beyond that detected during the initial outbreak investigation

Persistence of Antibodies against Middle East Respiratory Syndrome Coronavirus

To determine how long antibodies against Middle East respiratory syndrome coronavirus persist, we measured long-term antibody responses among persons serologically positive or indeterminate after a 2012 outbreak in Jordan. Antibodies, including neutralizing antibodies, were detectable in 6 (86%) of 7 persons for at least 34 months after the outbreak