Filter and nested-lattice code design for fading MIMO channels with side-information

Linear-assignment Gel'fand-Pinsker coding (LA-GPC) is a coding technique for channels with interference known only at the transmitter, where the known interference is treated as side-information (SI). As a special case of LA-GPC, dirty paper coding has been shown to be able to achieve the optimal interference-free rate for interference channels with perfect channel state information at the transmitter (CSIT). In the cases where only the channel distribution information at the transmitter (CDIT) is available, LA-GPC also has good (sometimes optimal) performance in a variety of fast and slow fading SI channels. In this paper, we design the filters in nested-lattice based coding to make it achieve the same rate performance as LA-GPC in multiple-input multiple-output (MIMO) channels. Compared with the random Gaussian codebooks used in previous works, our resultant coding schemes have an algebraic structure and can be implemented in practical systems. A simulation in a slow-fading channel is also provided, and near interference-free error performance is obtained. The proposed coding schemes can serve as the fundamental building blocks to achieve the promised rate performance of MIMO Gaussian broadcast channels with CDIT or perfect CSITComment: submitted to IEEE Transactions on Communications, Feb, 200

Clean relaying aided cognitive radio under the coexistence constraint

We consider the interference-mitigation based cognitive radio where the primary and secondary users can coexist at the same time and frequency bands, under the constraint that the rate of the primary user (PU) must remain the same with a single-user decoder. To meet such a coexistence constraint, the relaying from the secondary user (SU) can help the PU's transmission under the interference from the SU. However, the relayed signal in the known dirty paper coding (DPC) based scheme is interfered by the SU's signal, and is not "clean". In this paper, under the half-duplex constraints, we propose two new transmission schemes aided by the clean relaying from the SU's transmitter and receiver without interference from the SU. We name them as the clean transmitter relaying (CT) and clean transmitter-receiver relaying (CTR) aided cognitive radio, respectively. The rate and multiplexing gain performances of CT and CTR in fading channels with various availabilities of the channel state information at the transmitters (CSIT) are studied. Our CT generalizes the celebrated DPC based scheme proposed previously. With full CSIT, the multiplexing gain of the CTR is proved to be better (or no less) than that of the previous DPC based schemes. This is because the silent period for decoding the PU's messages for the DPC may not be necessary in the CTR. With only the statistics of CSIT, we further prove that the CTR outperforms the rate performance of the previous scheme in fast Rayleigh fading channels. The numerical examples also show that in a large class of channels, the proposed CT and CTR provide significant rate gains over the previous scheme with small complexity penalties.Comment: 30 page

Multi-user lattice coding for the multiple-access relay channel

This paper considers the multi-antenna multiple access relay channel (MARC), in which multiple users transmit messages to a common destination with the assistance of a relay. In a variety of MARC settings, the dynamic decode and forward (DDF) protocol is very useful due to its outstanding rate performance. However, the lack of good structured codebooks so far hinders practical applications of DDF for MARC. In this work, two classes of structured MARC codes are proposed: 1) one-to-one relay-mapper aided multiuser lattice coding (O-MLC), and 2) modulo-sum relay-mapper aided multiuser lattice coding (MS-MLC). The former enjoys better rate performance, while the latter provides more flexibility to tradeoff between the complexity of the relay mapper and the rate performance. It is shown that, in order to approach the rate performance achievable by an unstructured codebook with maximum-likelihood decoding, it is crucial to use a new K-stage coset decoder for structured O-MLC, instead of the one-stage decoder proposed in previous works. However, if O-MLC is decoded with the one-stage decoder only, it can still achieve the optimal DDF diversity-multiplexing gain tradeoff in the high signal-to-noise ratio regime. As for MS-MLC, its rate performance can approach that of the O-MLC by increasing the complexity of the modulo-sum relay-mapper. Finally, for practical implementations of both O-MLC and MS-MLC, practical short length lattice codes with linear mappers are designed, which facilitate efficient lattice decoding. Simulation results show that the proposed coding schemes outperform existing schemes in terms of outage probabilities in a variety of channel settings.Comment: 32 pages, 5 figure

An Investigation on Network Relationship of Elderly Nursing Home

All developed countries have been facing the trend of aging population and view it as an importance social policy which has to plan care and nurse senior citizens. The elderly caring and nursing organizations are obligated to provide more comfortable and suitable environment for a high quality life of elders. Based upon Maslow’s Hierarchy of Needs Theory, there is a hierarchy of five needs within each individual, including physiological needs, safety needs, belongingness and love Needs, self-esteem needs and self-actualization needs. Individuals would acquire emotional support, materiality and service through social network. This study investigates two main issues related to network relationship of elderly nursing home. First, this study demonstrates the network relationship between elderly nursing home and other related groups, including family and friends of elderly resident, exclusive volunteers, neighborhood community centre, religion groups and other welfare associations. Second, this study investigates what the network relationships would influence the satisfaction of five elderly residents’ needs. To better understanding the real connection among groups related to nursing home, this study uses case study with the perceptions of social network to know the network relationship in the nursing home and what it influences their residents’ needs

Relationships between Secondary School Students’ Perceptions of School Adjustment and Well-being

The research is financed by the Ministry of Science and Technology, Taiwan. No. MOST 108-2410-               H-018-016-MY2 Abstract Both school adjustment and well-being are fundamental to a good quality of life for youth. Good school adjustment is important and has far-reaching influences on the psychology and behavior of middle school students, which sets the stage for future educational and occupational opportunities. Good mental health or well-being helps young people develop the skills they need to cope with whatever life throws at them. The purposes of this study were to explore the relationships between secondary school students’ perceptions of school adjustment and well-being. 890 secondary students were selected from central Taiwan. A questionnaire was applied to collect data. Data were analyzed by using descriptive statistics, one-way ANOVA, Pearson’s product-moment correlation, and multiple regression analysis. The findings of this study were as follows: First, students’ perceptions of school adjustment and well-being were moderate level. Second, respondents with different family socio-economic status showed significant differences in school adjustment including dimensions of overall, academic adjustment, proper behavior, and self-affirmation, and also showed significant differences in well-being including dimensions of overall, life satisfaction, physical-mental health, and self-evaluation. Third, there was a medium positive correlation between respondents' school adjustment and well-being. The school adjustment could predict well-being and the peer relationship and the self-assurance were the better predictors of well-being. Keywords: Secondary school students, School adjustment, Well-being DOI: 10.7176/JEP/11-30-19 Publication date:October 31st 202