HP-SFC Algorithm for MmWave Massive MIMO Hybrid Precoding Systems

This paper presents an alternating iteration hybrid precoding algorithm for the switch network-based dynamic fully-connected (SFC) structure, namely HP-SFC algorithm. Firstly, based on the sparsity of switch network, the optimization problem of the analog switch precoding matrix is transformed into a binary dictionary updating problem, which avoids to deal with the binary constraint straightly. Then, the optimization problem of the analog phase shifter (PS) precoding matrix is modeled as a quadratic unimodular programming problem by the vectorization of the analog PS precoding matrix. So that the analog PS precoding matrix can be readily optimized. Finally, the analog switch precoding matrix, the analog PS precoding matrix and the digital precoding matrix are alternately optimized via the block coordinate descent, the generalized power method and the least square, respectively. Theoretical analysis and simulation results show that the proposed algorithm can provide brilliantly hybrid precoding performence campared with the previous works, for example: 1) it reduces the hybrid precoding matrix residual, so that its spectral efficiency is close to the full digital optimal precoding; 2) it provids at least 15\% energy efficiency improvement comparing with related algorithms.

Nonvolatile Analog Switch for Low-Voltage Applications

In this paper, a nonvolatile switch based on n-type floating-gate transistors is described. The switch states are programmed through the memory cell floating-gate voltage, allowing higher levels than the application supply. Furthermore, due to its nonvolatile nature, the power consumption is reduced. The on-state resistance, which does not depend on the supply voltage, is one of the greatest advantages of this type of switch in comparison to conventional switches. This benefit can be successfully exploited in low-voltage applications. The switch on-resistance can be increased without the need for increasing the switch area. The characteristics of the proposed switch were confirmed by the experimental results obtained on a test chip fabricated in a 0.18 µm EEPROM process. Measured on-resistance values between 45 and 70 Ω were obtained for a floating-gate voltage of 6.2 V and input source levels below 2 V. The required programming voltage was 18 V. The maximum off-state leakage current was measured at 5 nA.

Implementasi Rumah Pintar dengan Penggabungan Jalur Analog Digital Menggunakan Raspberry Pi

Teknologi internet of things menawarkan berbagai kemudahan bagi manuasia merupakan terobosan baru yang sangat bermafaat untuk kehidupan. Kesibukan pekerjaan yang begitu padat seringkali memaksa untuk banyak meninggalkan rumah dalam keadaan kosong. Tidak jarang rumah yang ditinggalkan dalam keadaan kosong menjadi sasaran pencuri ataupun bahaya kebakaran. Kasus kebakaran saat yang terjadi saat ini sebagian besar dipicu akibat kebocoran gas konsleting listrik dan pemilik rumah lupa mematikan alat listrik saat meninggalkan rumah. Tetapi masyarakat juga masih ragu jika sistem digital mengalami kendala yang harus dilakukan. Sebagai solusi dari keadaan tersebut maka diperlukan alat yang bisa mengontrol rumah dari jarak jauh menggunakan jaringan internet. Hal ini diharapkan dapat mencegah terjadinya hal yang tidak diinginkan. Untuk mewujudkannya, penulis melakukan riset untuk membangun sebuah sistem rumah pintar yang nantinya semua peralatan listrik dan elektronik dapat dikontrol menggunakan smartphone menggunakan jaringan internet yang menggunakan fungsi switch analog digital. Tujuan lainnya adalah membuat sebuah produk smart home yang cocok di aplikasikan di Indonesia yang nantinya smart home tersebut tidak meniggalkan saklar konvensional yang sudah terpasang dirumah. Penelitian ini berhasil merancang sebuah sistem rumah pintar yang dapat di bypass menjadi sistem listrik analog. Hal ini untuk mengantisipasi ketika terjadi error pada sistem digital sehingga kelistrikan rumah masih dapat berjalan seperti biasa. Kata Kunci— rumah pintar, pengontrol listrik, analog, digital.AbstractInternet technology about things that offer various conveniences for people today is a new breakthrough that is very useful for human life. The bustle of work is so crowded while waiting to go home. There is no damaged house there. Very important for homeowners. The current fire cases are mostly triggered by a gas leak and the homeowner forgets to turn off the electricity when leaving the house. However, the public is still in doubt if a digital system is being done which must be done. As a solution to this situation, we need a tool that can control the house remotely using the internet network. This is expected to be avoided. Unwanted things. To realize this, the authors conducted research to build a smart home system that allows all electrical and electronic equipment to be controlled using a smartphone that uses the internet network provided by a digital analog switch. Not only that, smart home makers that are suitable to be applied in Indonesia while smart homes do not leave conventional diversions installed at home. This research successfully completed a smart home system that can cut bypass into an analog electrical system. This is to correct errors that occur in digital systems so that electricity can still run as usual. Keywords—Smart home, electric controller, analog, digital.

Simultaneous Acquisition of Ultrasound and Gamma Signals with a Single-Channel Readout

We propose an integrated front-end data acquisition circuit for a hybrid ultrasound (US)-gamma probe. The proposed circuit consists of three main parts: (1) a preamplifier for the gamma probe, (2) a preprocessing analog circuit for the US, and (3) a digitally controlled analog switch. By exploiting the long idle time of the US system, an analog switch can be used to acquire data of both systems using a single output channel simultaneously. On the nuclear medicine (NM) gamma probe side, energy resolutions of 18.4% and 17.5% were acquired with the standalone system and with the proposed switching circuit, respectively, when irradiated with a Co-57 radiation source. Similarly, signal-to-noise ratios of 14.89 and 13.12 dB were achieved when US echo signals were acquired with the standalone system and with the proposed switching circuit, respectively. Lastly, a combined US-gamma probe was used to scan a glass target and a sealed radiation source placed in a water tank. The results confirmed that, by using a hybrid US-gamma probe system, it is possible to distinguish between the two objects and acquire structural information (ultrasound) alongside molecular information (gamma radiation source).