EM Algorithm Based MAP Channel Estimation for Multi-Cell Massive MIMO Systems

This paper represents an efficient expectation-maximization (EM) algorithm based maximum a posteriori (MAP) channel estimation method for multi-cell massive multiple input multiple output (MIMO) systems. MAP channel estimation method requires conjugate transpose of a T x K pilot matrix where T is the number of pilot symbols per user and K is the number of single antenna users. Conjugate transpose of large-size matrix increases computational complexity. The proposed method estimates the channel iteratively and converges to the same mean square error (MSE) performance of the MAP estimator with the increasing number of iterations. Consequently, the proposed method with low-rank approximation avoids conjugate transpose of large-size matrix and hence reduces the computational complexity significantly

SAGE Algorithm Based MAP Channel Estimation for Multi-Cell Massive MIMO Systems

This paper represents an efficient space-alteraing generalized expectation-maximization (SAGE) algmorithm based maximum a posteriori (MAP) channel estimation method for multi-cell massive multiple input multiple output (MIMO) sytems. MAP channel estimation method requires conjugate transpose of a tau x K pilot matrix where tau is the number of pilot symbols per user and K is the number of single antenna users. Conjugate transpose of the large-size matrix increases computational complexity. The proposed method estimates the channel iteratively and converges to the same mean square error (MSE) performance of the MAP estimator with the increasing number of iterations. Consequently, the proposed method with low-rank approximation avoids conjugate transpose of the large-size matrix and hence reduces the computational complexity significantly

Demographics of patients with heart failure who were over 80 years old and were admitted to the cardiology clinics in Turkey

WOS: 000468584300005PubMed ID: 30930455Objective: Heart failure (HF) has a high prevalence and mortality rate in elderly patients; however, there are few studies that have focused on patients older than 80 years. The aim of this study is to describe and compare the age-specific demographics and clinical features of Turkish elderly patients with HF who were admitted to cardiology clinics. Methods: The Epidemiology of Cardiovascular Disease in Elderly Turkish population (ELDER-TURK) study was conducted in 73 centers in Turkey, and it recruited a total of 5694 patients aged 65 years or older. In this study, the clinical profile of the patients who were aged 80 years or older and those between 65 and 79 years with HF were described and compared based on the ejection fraction (EF)-related classification: HFrEF and HFpEF (is considered as EF: >= 50%). Results: A total of 1098 patients (male, 47.5%; mean age, 83.5 +/- 3.1 years) aged 80 years and 4596 patients (male, 50.2 %; mean age, 71.1 +/- 4.31 years) aged 65-79 years were enrolled in this study. The prevalence of HF was 39.8% for patients who were >= 80 years and 27.1% for patients 65-79 years old. For patients aged >= 80 years with HF, the prevalence rate was 67% for hypertension (HT), 25.6% for diabetes mellitus (DM), 54.3% for coronary artery disease (CAD), and 42.3% for atrial fibrilation. Female proportion was lower in the HFrEF group (p=0.019). The prevalence of HT and DM was higher in the HFpEF group (p= 80 years with HFrEF (p<0.01). Conclusion: HF is common in elderly Turkish population, and its frequency increases significantly with age. Females, diabetics, and hypertensives are more likely to have HFpEF, whereas CAD patients are more likely to have HFrEF.Turkish Society of CardiologyThis study was supported by Turkish Society of Cardiology

Incidence and clinical characteristics of acute rheumatic fever in Turkey: Results of a nationwide multicentre study

© 2021 Paediatrics and Child Health Division (The Royal Australasian College of Physicians)Aim: To evaluate the incidence and clinical features of acute rheumatic fever (ARF) in Turkey, following the revised Jones criteria in 2015. Methods: This multicentre study was designed by the Acquired Heart Diseases Working Group of the Turkish Pediatric Cardiology and Pediatric Cardiac Surgery Association in 2016. The data during the first attack of 1103 ARF patients were collected from the paediatric cardiologists between 1 January 2016 and 31 December 2016. Results: Turkey National Institute of Statistics records of 2016 were used for the determination of ARF incidence with regard to various cities and regions separately. The estimated incidence rate of ARF was 8.84/100 000 in Turkey. The ARF incidence varied considerably among different regions. The highest incidence was found in the Eastern Anatolia Region as 14.4/100 000, and the lowest incidence was found in the Black Sea Region as 3.3/100 000 (P < 0.05). Clinical carditis was the most common finding. The incidence of clinical carditis, subclinical carditis, polyarthritis, aseptic monoarthritis, polyarthralgia and Sydenham's Chorea was 53.5%, 29.1%, 52.8%, 10.3%, 18.6% and 7.9%, respectively. The incidences of clinical carditis, subclinical carditis, polyarthritis and polyarthralgia were found to be significantly different among different regions (P < 0.05). Conclusion: The findings of this nationwide screening of ARF suggest that Turkey should be included in the moderate-risk group

Demographics of patients with heart failure who were over 80 years old and were admitted to the cardiology clinics in Turkey

Objective: Heart failure (HF) has a high prevalence and mortality rate in elderly patients; however, there are few studies that have focused on patients older than 80 years. The aim of this study is to describe and compare the age-specific demographics and clinical features of Turkish elderly patients with HF who were admitted to cardiology clinics. Methods: The Epidemiology of Cardiovascular Disease in Elderly Turkish population (ELDER-TURK) study was conducted in 73 centers in Turkey, and it recruited a total of 5694 patients aged 65 years or older. In this study, the clinical profile of the patients who were aged 80 years or older and those between 65 and 79 years with HF were described and compared based on the ejection fraction (EF)-related classification: HFrEF and HFpEF (is considered as EF: >= 50\%). Results: A total of 1098 patients (male, 47.5\%; mean age, 83.5 +/- 3.1 years) aged 80 years and 4596 patients (male, 50.2 \%; mean age, 71.1 +/- 4.31 years) aged 65-79 years were enrolled in this study. The prevalence of HF was 39.8\% for patients who were >= 80 years and 27.1\% for patients 65-79 years old. For patients aged >= 80 years with HF, the prevalence rate was 67\% for hypertension (HT), 25.6\% for diabetes mellitus (DM), 54.3\% for coronary artery disease (CAD), and 42.3\% for atrial fibrilation. Female proportion was lower in the HFrEF group (p=0.019). The prevalence of HT and DM was higher in the HFpEF group (p<0.01), whereas CAD had a higher prevalence in the HFrEF group (p=0.02). Among patients aged 65-79 years, 43.9\% (548) had HFpEF, and 56.1\% (700) had HFrEF. In this group of patients aged 65-79 years with HFrEF, the prevalence of DM was significantly higher than in patients aged >= 80 years with HFrEF (p<0.01). Conclusion: HF is common in elderly Turkish population, and its frequency increases significantly with age. Females, diabetics, and hypertensives are more likely to have HFpEF, whereas CAD patients are more likely to have HFrEF