Multi RF Research Articles

Analysis of multimedia network data security based on routing algorithm

In today’s society, the application of multimedia data is increasing, and the accompanying data security is also an important issue. This paper will analyze the data security of multimedia network based on routing algorithm. The advantages of wireless local area networks (WLAN) and ad hoc networks are combined in wireless mesh networks (WMNs), which have steadily grown to be a reliable method of wireless broadband access. The application of multi RF and multi-channel technology improves the performance of WMN. However, the limitation that includes the number of wireless network interface cards and channels in the network, results in the great challenges ofrouting and channel allocation in multi RF and multi-channel WMN. Based on AODV algorithm, this paper proposes a new cross layer routing algorithm which is JRCA-AODV algorithm. The simulation results demonstrate that the JRCA-AODValgorithm can successfully increase multiRF multi-channel WMN throughput while lowering packet loss rate and network delay. Take the packet rate of 8 Mbps as an example, the network throughput based on JRCA-AODV algorithm is 1.14 times that of MRMC-AODV algorithm, the packet loss rate based on JRCA-AODV algorithm is 14.06% lower than that of MRMC-AODV algorithm, and the network time delay based on JRCA-AODV algorithm is 14.27% lower than that of MRMC-AODV algorithm. At the same time, JRCA-AODV algorithm can effectively reduce the probability of data loss caused by the competitive and shared access mechanism of the channel, improve the success rate of data transmission, thus reduce the probability of data eavesdropping and tampering in the process of repeated transmission, and improve the security of multimedia network data.This will provide a new direction for promoting the idea of multimedia data security.

Energy efficient degree of freedom aided multi beam transmit antenna precoding for mmWave MIMO system

Millimeter-wave communication system provides the feasible solution for the bandwidth limitation present in the sub 6-GHz system. This millimeter-wave communication system requires large antenna array for transmission and needs better RF chain utilization methods. Often single beam transmission over multiple antennas are deployed for RF chain reduction and inter user interference reduction. Multi beam Multi RF transmission system despite capable of providing maximum capacity is affected by power leakage and hence experiences poor energy efficiency. A Multi Beam Transmit Antenna Precoding for Multi beam Multi RF mmWave MIMO system based on analog power splitter arrangement was proposed instead of existing large digital switching network to reduce complexity. In this Multi Beam Transmit Antenna Precoder setup four new precoding algorithms based on alamouti, hadamard, toeplitz and zero correlation sequence were proposed. Sum rate and energy efficiency of the proposed methods were derived theoretically, simulated and compared with existing methods. Computational complexity and degree of freedom were also analyzed for the proposed methods.

Multi-RF and Generalized Single-RF Combination Models for Spatial Modulation and NOMA Technologies

Inspired by the individual advantages of spatial modulation (SM), space shift keying (SSK), and non-orthogonal multiple access (NOMA) technologies, this research designs NOMA-SM/SSK amalgamation models with a general number of users. Based on the number of RF chains, they are classified into multi-RF (MRF) and single-RF (SRF) models. We first present a spectral-efficient MRF model and then propose a new energy-efficient generalized SRF model denoted as SRFGen. In SRFGen, all users jointly choose a shared transmit antenna (TA) and independently select their modulation symbols. The SRFGen's flexibility produces several special cases covering the literature on SRF models and resolves their limits. Among the scenarios, an SRF NOMA-SSK supports multi <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-</i> SSK signals and is proposed to reduce interference and detection processes. Then, introduce a low complexity TA index detector and an adaptive and fair power allocation algorithm. The spectral efficiency (SE) of the MRF and SRFGen is analyzed with lower bounds for both Gaussian and finite-alphabet inputs. Using the SE analysis and bit-error-rate (BER) simulation, the NOMA-SM/SSK models are evaluated regarding users’ rates, sum-rate, ergodic capacity, and BER. The results show that the MRF grants high SE, whereas the SRFGen provides flexibility in trading-off features like SE, BER, users’ fairness, and detection complexity. The outcomes also reveal the superior performance of the presented SRF models compared to the literature SRF models. Besides, the results reinforce the superiority of NOMA-SM/SSK over OMA-SM.

RF devices: from WLSCP to smart interposers

RF wireless devices such as 3G/4G, Wifi, Bluethooth etc... represent today 32% of the whole WLCSP products which know a steady grow above 10% per year [1]. However, a clear trend of combining multi RF chips in one WLCSP module is emerging. This allows shorter RF connections, reduction of BOM and diminution of the overall cost. Complex and heterogeneous RF systems will become possible allowing soon tunability. A silicon package directly reported on board is a good candidate to meet these next challenges of RF WLCSP. Indeed, low cost and multi-chips interposers will soon be produced by TSV fabs or OSATs and tunables devices could be reported on them. But the direct report on board as well as the high frequency signal integrity must be first evaluated carefully. In this work, we describe promising results of silicon package based on high resistive silicon interposer encompassing 2 levels of Cu Damascene, Tx/Rx antenna, one RF chip and TSV last for 60GHz applications. A new wafer-level molding [2] is performed on front side by lamination at wafer level. On the backside of the interposer, thick Cu RDL and soft layer passivation is deposited before the balling. Just like in WLSCP, different kinds of solder balls are mounted and analyzed with respect to their size (350 or 400 μm) or type (solder or polymer/solder). The passivated interposers are diced and then reported on a PCB, thus forming the silicon package. Low Rf loss (&amp;lt;1dB) attenuation is demonstrated for the routing layers while the antennas exhibit a suitable gain of 5dBi over the 55–65 GHz band. The assembly characteristics between the silicon package and the board will be discussed with respect to the different chosen design rules. These first results pave the way to a new kind of smart package based on Si interposers, moving forward to more complex WLCSP RF devices.