Objective: Medication reconciliation (MedRec) can improve patient safety by resolving medication discrepancies. Because information technology (IT) and patient engagement are promising approaches to optimizing MedRec, the SEAMPAT project aims to develop a MedRec IT platform based on two applications: the "patient app" and the "MedRec app." This study evaluates three dimensions of the usability (efficiency, satisfaction, and effectiveness) and usefulness of the patient app. Methods: We performed a four-month user-centered observational study. Quantitative and qualitative data were collected. Participants completed the system usability scale (SUS) questionnaire and a second questionnaire on usefulness. Effectiveness was assessed by measuring the completeness of the medication list generated by the patient application and its correctness (ie medication discrepancies between the patient list and the best possible medication history). Qualitative data were collected from semi-structured interviews, observations and comments, and questions raised by patients. Results: Forty-two patients completed the study. Sixty-nine percent of patients considered the patient app to be acceptable (SUS Score ≥ 70) and usefulness was high. The medication list was complete for a quarter of the patients (7/28) and there was a discrepancy for 21.7% of medications (21/97). The qualitative data enabled the identification of several barriers (related to functional and non-functional aspects) to the optimization of usability and usefulness. Conclusions: Our findings highlight the importance and value of user-centered usability testing of a patient application implemented in "real-world" conditions. To achieve adoption and sustained use by patients, the app should meet patients' needs while also efficiently improving the quality of MedRec.

To enable frequency domain equalization of continuous phase modulations (CPM), a block construction that ensures cyclicity over each block without disrupting the phase continuity between them was proposed in . We formalize and prove the constraints that should be respected to enable the application of this technique to any CPM scheme.

The large bandwidth available at 60 GHz together with the resulting wavelength of only 5 mm allow the design of multi-Gbps wireless devices equipped with large arrays of tiny antennas. This enables wireless communication of large contents multimedia such as high-definition video. However, due to the high cost and power consumption of analog frond-end (AFE) chains at 60 GHz, it is practically infeasible to allocate a dedicated AFE to each antenna. Thus, it is highly desirable to design low complexity multi-antenna architectures in which an analog linear transformation (ALT) is carried out in order to reduce the required number of AFE chains for digital spatial processing, while minimizing the capacity loss. In this paper, we propose a non-iterative algorithm for joint transmit/receive (TX/RX) ALT. The proposed algorithm is designed with the aim of maximizing the capacity of the resulting reduced dimension MIMO system, assuming a frequency selective propagation channel.

Multi-antenna architectures, where beamforming processing is shared between analog and digital, are of great interest for future multi-Gbps wireless systems operating at 60 GHz. In this spectrum band, wireless systems can integrate large antenna arrays in a very small volume thanks to a wavelength of about 5 mm and thus provide the required gain to meet the severe link budget. However, the cost and power consumption of an analog front-end (AFE) chain, that carries out translation between radio frequency (RF) and digital baseband, are too high at 60 GHz to afford one AFE for each antenna. In this paper, we consider low cost multi-antenna architectures with a lower number of AFE chains than antenna elements. We propose a joint design of transmit-receive mixed analog/digital beamformers that aim at maximizing the received average signal-to-noise-ratio (SNR). The proposed scheme shows better performance than state-of-art solutions, which combine antenna selection techniques and digital beamforming.

Analog beamforming (ABF) with one scalar weight per antenna is an attractive technique for low-cost, low-power 60 GHz multi-antenna wireless communication systems. However, the design of the corresponding joint transmit and receive (Tx/Rx) ABF optimization algorithms is still challenging in the case of multipath channels due to the constraint of having only one scalar weight per antenna. In this paper, we aim at maximizing the average signal to noise ratio (SNR) at the input of the equalizer and analytically derive close-to-optimal Tx/Rx scalar weights. We show that the required channel state information (CSI) for joint Tx/Rx ABF weights computation is the inner product between all Tx/Rx channel impulse response pairs. Taking the channel length into account, a training-based estimation strategy of this CSI is proposed. Simulation results carried out in a typical 60 GHz multipath environment show that the proposed scheme outperforms the existing ABF schemes in term of BER performances.

We present a new scheme for maximizing the signal-to-noise ratio (SNR) in wideband multi-antenna receivers that employ time-interleaved analog-to-digital converters (ADCs). Current wideband receivers interleave a fixed number of slower ADCs into one fast ADC and assign this latter to one antenna according to an antenna selection algorithm. However, this does not always guarantee an optimal trade-off between thermal noise and quantization noise. This results in an overall SNR that is lower than what could be obtained with the same number of ADCs, assigned in a more optimal way. Therefore, we propose to adjust the number of slower ADCs assigned to a certain fast, interleaved ADC dynamically, according to the SNR of every individual antenna. Our proposed algorithm can be implemented at the expense of a very limited hardware complexity increase. The SNR gain of our new scheme can exceed 7 dB, depending on channel conditions and ADC specifications.

In this paper, we develop a new low-complexity linear frequency domain equalization (FDE) approach for continuous phase modulated (CPM) signals. As a CPM signal is highly correlated, calculating a linear minimum mean square error (MMSE) channel equalizer requires the inversion of a nondiagonal matrix, even in the frequency domain. In order to regain the FDE advantage of reduced computational complexity, we show that this matrix can be approximated by a block-diagonal matrix without performance loss. Moreover, our MMSE equalizer can be simplified to a low-complexity zero-forcing equalizer. The proposed techniques can be applied to any CPM scheme. To support this theory we present a new polyphase matrix model, valid for any block-based CPM system. Simulation results in a 60 GHz environment show that our reduced-complexity MMSE equalizer significantly outperforms the state of the art linear MMSE receiver for large modulation indices, while it performs only slightly worse for small ones.

Continuous phase modulations (CPM) have a perfectly constant envelope and are inherently robust against analog front-end nonidealities. Therefore, they have recently been proposed for several modern wireless standards. In this paper, we further develop an existing high-performance frequency domain equalization approach for CPM signals. First, we introduce a polyphase matrix model, valid for any block-based CPM system, which has clear advantages compared to existing models. Second, the model is used to reduce the complexity of the existing minimum mean square error channel equalizer. The proposed technique can be applied to any CPM scheme. Simulation results in a 60 GHz environment confirm that it does not cause any noticeable performance degradation.

In this paper, we present an analytical analysis to predict the power spectral density (PSD) at the output of a nonlinear power amplifier (PA). We focus on offset quadrature phase shift keying (OQPSK) waveform band-limited by a square root raised cosine (SRRC) filter. This is one of the waveforms used in wideband code division multiple access (W-CDMA) wireless standard. We show that the PA output PSD obtained by our analytical analysis matches well the simulated PSD. Furthermore, we compare the PA output PSD of QPSK and OQPSK waveforms as a function of the SRRC filter roll-off. We conclude that for small roll-off, both QPSK and OQPSK experience almost the same level of spectral re-growth. As the roll-off increases, OQPSK becomes less sensitive to PA nonlinearity relative to QPSK.

We show how to apply Frequency Domain Equalization (FDE) to precoded Continuous Phase Modulation (CPM) systems. It is well known that differential precoding can be applied to the specific, popular class of CPM schemes with modulation index h = 1/2Q, where Q is any integer. This precoding halves the bit error rate (BER) compared to nonprecoded CPM without any overhead or complexity increase. We apply FDE to a block-based precoded CPM system. Therefore, we show that in addition to a cyclic prefix, two subblocks of data-dependent symbols have to be inserted in each block to cope with the memory in the CPM signal and to enable correct decoding by the receiver. We explain how to calculate these subblocks. Simulation results in a 60 GHz environment confirm that the BER is halved by precoding, and that this precoding is compatible with FDE using our new technique.

We present a new symbol block construction which yields a cyclic continuous phase modulated (CPM) signal to enable frequency domain equalization. It is known that in addition to a cyclic prefix, a subblock of data-dependent symbols has to be inserted in each block to cope with the memory in the CPM signal. We propose a new subblock, called intrafix, valid for any CPM scheme. Our intrafix is shorter than what is currently known in the literature, reducing the overhead. Moreover, it can be calculated on a per-block basis, without knowledge of previous blocks. We also prove that there are constraints on the length of both the intrafix and the total block by studying the influence of the modulation index. Simulation results in a 60 GHz environment show that our new block construction satisfies all requirements.

A new approach for frequency-domain equalization of continuous phase modulated (CPM) signals is presented. In contrast with state-of-the-art receivers, we separate channel equalization on the one hand and CPM demodulation on the other. This separation enables us to calculate independently of the CPM scheme a new low-complexity zero-forcing channel equalizer. We also present a new high-performance minimum mean square error (MMSE) channel equalizer for any CPM scheme and a method to lower its complexity for a popular class of CPM schemes. Simulations show that our new MMSE equalizer significantly outperforms state-of-the-art linear receivers in a 60 GHz multipath environment.

Single-carrier with cyclic prefix (SC-CP) is seen as an interesting air interface to replace orthogonal frequency- division multiplexing (OFDM) because it features a lower peak- to average power ratio (PAPR) while still allowing low complexity frequency domain equalization (FDE). Both air interfaces are highly sensitive to phase noise (PN) that degrades their system performances. In this paper, we study and compare analytically the PN impact on both air interfaces. Simulations are also carried out to validate the analytical results. PN causes the same common phase error (CPE) on both air interfaces, as well as it leads to Inter-Carrier Interference (ICI) in OFDM and inter-symbol interference (ISI) in SC-CP. However OFDM is found to be slightly less affected than SC-CP in both flat channels and frequency selective channels. It is shown also that CPE is the dominate impact if the PN cut-off frequency is smaller than the subcarrier spacing.

Multilevel continuous phase modulated (CPM) signals feature a perfectly constant envelope, attractive spectral properties and excellent power efficiency. However, their non-linear nature makes them less tractable and their processing more complex. Fortunately, a linear decomposition exists, allowing to apply linear signal processing techniques. This decomposition was originally developed for binary CPM schemes only, and is not suited for schemes with an integer modulation index. It was extended to multilevel CPM schemes, by decomposing the multilevel input sequence in a product of binary subsequences, and applying the binary decomposition to these subsequences. When one or more of these subsequences has an integer modulation index though, this technique fails. We present a general solution, and prove how many pulses are needed to represent the CPM signal in this particular case. The decomposition of the quaternary 3RC system with h = 1/2 is given as an example. A receiver based on this solution is presented.

The huge bandwidth available at 60 GHz will allow short range wireless communication to deliver bit rates over 1 Gbps. However the design of millimeter wave analog blocks is more critical than at lower frequencies, leading to a possible high non ideality of the radio front-end (FE). A suitable air interface for low cost, low power 60 GHz transceivers should thus use a modulation technique that has a high level of immunity to FE non-idealities. In this paper, we compare the sensitivity to FE non-idealities of two promising air interfaces namely offset quadrature phase shift keying (OQPSK) with frequency domain equalization (FDE) and continuous phase modulation (CPM) with time domain equalization (TDE). Our study focus on three main analog imperfections that are likely to have the biggest impact on the overall system performance: phase noise generated by the voltage control oscillator (VCO), clipping and quantization errors caused by the analog-to-digital converter (ADC) and non-linearity in the power amplifier (PA). Results show that CPM based air interface is more robust than OQPSK-based regarding the FE non-idealities. However the latter is less complex to design and offers much higher data rate than the former in the same bandwidth.