T A Q

Code without a message (taq), animation and stills

Massive MIMO with I/Q imbalance: Performance analysis and compensation

In this paper, we consider the uplink of a single-cell massive multiple-input multiple-output (MIMO) system with inphase and quadrature-phase imbalance (IQI). This scenario is of particular importance in massive MIMO systems, where the deployment of lower-cost, lower-quality components is desirable to make massive MIMO a viable technology. Particularly, we investigate the effect of IQI on the performance of massive MIMO employing maximum-ratio combining (MRC) receivers. In order to study how IQI affects channel estimation, we derive a new channel estimator for the IQI-impaired model and show that IQI can substantially downgrade the performance of MRC receivers. Moreover, a low-complexity IQI compensation scheme, suitable for massive MIMO, is proposed which is based on the IQI coefficients' estimation and it is independent of the channel gain. The performance of the proposed compensation scheme is analytically evaluated by deriving a tractable approximation of the ergodic achievable rate and providing the asymptotic power scaling laws assuming transmission over Rayleigh fading channels with log-normal large-scale fading. Finally, we show that massive MIMO effectively suppresses the residual IQI effects, as long as, the compensation scheme is applied.

I/Q imbalance in two-way AF relaying: Performance analysis and detection mode switch

This paper studies the impact of in-phase and quadrature-phase imbalance (IQI) in two-way amplify-and-forward (AF) relaying systems. In particular, the effective signal-to-interference-plus-noise ratio (SINR) is derived for each source node, considering four different linear detection schemes, namely, uncompensated (Uncomp) scheme, maximal-ratio-combining (MRC), zero-forcing (ZF) and minimum mean-square error (MMSE) based schemes. For each proposed scheme, the outage probability (OP) is investigated over independent, non-identically distributed Nakagami-m fading channels, and exact closed-form expressions are derived for the first three schemes. Based on the closed-form OP expressions, an adaptive detection mode switching scheme is designed for minimizing the OP of both sources. An important observation is that, regardless of the channel conditions and transmit powers, the ZF-based scheme should always be selected if the target SINR is larger than 3 (4.77dB), while the MRC-based scheme should be avoided if the target SINR is larger than 0.38 (-4.20dB).

I/Q imbalance in two-way AF relaying: Power allocation and performance analysis

We investigate the performance of dual-hop two-way amplify-and-forward (AF) relaying in the presence of inphase and quadrature-phase imbalance (IQI) at the relay node. In particular, the effective signal-to-interference-plus-noise ratio (SINR) at both sources is derived. These SINRs are used to design an instantaneous power allocation scheme, which maximizes the minimum SINR of the two sources under a total transmit power constraint. The solution to this optimization problem is analytically determined and used to evaluate the outage probability (OP) of the considered two-way AF relaying system. Both analytical and numerical results show that IQI can create fundamental performance limits on two-way relaying, which cannot be avoided by simply improving the channel conditions.

Conciliorum omnium, tam generalium q[uam] particulariu[m] : a temporibus Agapeti papæ vsque ad Eugenium papam quartu[m], ex vetustissimis bibliothecis collectorum : tomus secundus, quorum ordinem & nomina versa pagina quærentibus offeret.

Colofón

On (p, q) − equations with concave terms

We consider a (p, q)− equation (1 < q < p, p ≥ 2) with a parametric concave term and a (p − 1)− linear perturbation. We show that the problem have five nontrivial smooth solutions: four of constant sign and the fifth nodal. When q = 2 (i.e., (p, 2) equation) we show that the problem has six nontrivial smooth solutions, but we do not specify the sign of the sixth solution. Our approach uses variational methods, together with truncation and comparison techniques and Morse theory.

Nursing facility MDS Section Q Fact Sheet, February 29, 2016

MDS section Q - Q&A

Nursing Facility MDS Section Q Informational Sheet, February 21, 2014

Information regarding Section Q - referrals and when appropriate

Minimum Data Set (MDS) Section Q Education: Helping People Return to the Community, February 12, 2014

Explanation of Minimum Data Set (MDS), implementation of Section Q, overview of the program, local contacts and functions, Referral Agency information, role and assistance provided by Long-Term care Ombudsman

Minimum Data Set (MDS) Section Q Education, February 21, 2014

Information regarding possible questions on Section Q within the Minimum Data Set.

CIL 3.566 – Dedication for Q. Minucius Rufus

Squeeze, photograph and notes by A.E. Gordon

Comparison of High Q microresonators operating on a thin plate mode : the Lamé-mode

International audience

Acute Q Fever Presenting with Multi-Organ Failure: Re-Evaluation of the Initial Diagnosis

We present the case of a 48-year-old man admitted to the critical care unit with atrial fibrillation, and acute heart and kidney failure accompanied by coagulopathy and an abnormal liver test. Initially diagnosed as a non-ST elevation myocardial infarction, re-evaluation of the case led to the consideration of severe sepsis. Q fever and leptospirosis were the most probable causes and empiric treatment was initiated. A complete recovery was achieved following treatment.

CIL 2.1459 – Dedication to Q. Memmius Quirina Niger

Photograph