Data rate based performance analysis and optimization of bulk OUT transactions in USB 3.0 SuperSpeed protocol

This paper investigates the downlink performance of indoor deployed Wi-Fi and Femto as the offloading solution to the LTE macro cellular networks in a realistic large-scale dense-urban scenario. With an assumed broadband traffic volume growth of 50x compared to today's levels, it is evaluated that a dual-carrier LTE macro network will not be able to provide sufficient service coverage with a 1 Mbps minimum data rate and, indoor coverage is identified as the major bottleneck.. We evaluate the performance of indoor Wi-Fi and Femto cell deployment to offload the congested LTE macro network. We show that, in a dual-carrier LTE macro case with a total of 30 MHz spectrum, Wi-Fi access point density of 230/km2 is required to meet the set target of 90% coverage with a minimum user data rate of 1 Mbps. For the same scenario it was found that an out-band Femto access point density of 1200/km2 is required. Furthermore, we show that in-band Femto cell cannot meet the set network requirement even at a very high access point density. We also show that Wi-Fi and Femto cell can offload the same amount of traffic when they are deployed at the same access point density.

In microwave systems, the phase noise is well known to be a significant source of degradation especially for low data rate transmission, giving rise to a significant irreducible error rate. In an earlier study [1,2] based on the European Space Agency's Olympus Satellite 30/20 GHz payload parameters, it was found that several thousands of simultaneous transmissions of 50 to 200 bits/sec each could be supported from hand-held pico-terminal earth stations. It is important to use the most appropriate modulation scheme in the presence of oscillator phase noise for such low data rate systems. It is generally assumed that noncoherent or differentially coherent modulation schemes will perform best in applications where the coherence time of the oscillators is short compared to the bit period. However, our analysis of these schemes has shown that they are subject to irreducible error rates and minimum useable data rates. This has led us to reconsider coherent BPSK (CPSK). It is shown that the choice of the optimum noise bandwidth of the phase locked loop (PLL) in the carrier recovery circuit is very important when considering the coherent schemes. The PLL bandwidth must be wide enough to track the oscillator phase noise at its input, but, on the other hand, it must be as narrow as possible to exclude the thermal noise. Results show that coherent BPSK in the phase noise contaminated channel is also subject to an irreducible error rate, which increases as the noise bandwidth is reduced. For the optimum loop bandwidth, however, this appears to be lower than the corresponding figure for DPSK [3]. There is a minimum useable data rate for any given bit error rate (BER) requirement. Results of a complete analysis are presented in the form of BER versusE b/N o plots.

A resource allocation algorithm for orthogonal frequency division multiple access-based and infrastructure-based relay networks is introduced in this paper. The algorithm is applied in the downlink of a single cell. Channel state information is exploited at the transmitting base station (BS) and at the transmitting relay stations (RSs). The algorithm coordinates the allocation of subcarriers, bits, and power distributed over the BS and RSs. The goal of the resource allocation algorithm is that the sum rate in a cell is maximized. Simultaneously, each subscriber station (SS) achieves a requested data rate called minimum data rate, and a tolerated bit error probability is ensured on each link. Simulation results show that a sum rate in a cell is achieved which is near to an upper bound introduced in the paper. Even if the sum of the minimum data rates of all SSs is large, the proposed algorithm offers the minimum data rate nearly as reliable as the upper bound. Additionally, simulation results show that the proposed algorithm achieves a superior sum rate compared to the sum rate of other resource allocation algorithms.

This letter addresses, for the first time, the uplink performance optimization of multi-user pinching-antenna (PA) systems, recently developed for next-generation wireless networks. By leveraging the unique capabilities of PAs to dynamically configure wireless channels, we focus on maximizing the minimum achievable data rate between devices to achieve a balanced trade-off between throughput and fairness. An effective approach is proposed that separately optimizes the positions of the PAs and the resource allocation. The antenna positioning problem is reformulated into a convex one, while a closed-form solution is provided for the resource allocation. Simulation results demonstrate the superior performance of the investigated system using the proposed algorithm over corresponding counterparts, emphasizing the significant potential of PA systems for robust and efficient uplink communication in next-generation wireless networks.

In cellular networks, cell size reduction is an important technique for improving the spectral reuse and achieving higher data rates. In addition, it results in power savings as it leads to a decrease in transmit power. However, it is not clear if the transmit power can be indefinitely decreased with the cell sizes. In this paper, we analyze the impact of transmit power reduction (cell size reduction) on the performance of the network. More precisely, we obtain a lower bound on the transmit power such that a minimum coverage and a minimum data rate can be guaranteed. We then analyze the area power consumption metric, which denotes the total power consumed per unit area. Under the constraints of target coverage and target data rate, the area power consumption is minimized and the optimal base station density is obtained. For a path loss exponent α > 4, we observe the existence of a minimum cell size below which shrinking the cell would result in an overall increase of power. However, for α ≤ 4, there exists no such optimal cell-size, as the area power consumption increases with base station density.

In digitally networked systems the assumption of classical control theory that information can be transmitted instantaneously, lossless and with arbitrary precision is violated. This raises the question about the smallest data rate above which a control task can be solved. For a single control loop and the problem to make a set Q of states invariant, the minimal data rate can be described by an entropy‐like quantity, the so‐called invariance entropy. Under some controllability and hyperbolicity assumptions, the invariance entropy can be expressed in terms of Lyapunov exponents. Furthermore, one can show that for making Q invariant with a data rate close to the smallest, no strategies more complicated than stabilization at periodic trajectories are necessary. For a network with n subsystems, which can all communicate with each other, there are different ways to formulate the question about the smallest data rate for the invariance problem, but also in this setting entropy‐like quantities yield important information. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Persistent efforts on developing advanced and complex data algorithms to enable the vertical-cavity surface-emitting lasers (VCSELs) for data beyond 100-Gbit/s has been reviewed in this paper. This endeavor not only elevates the bit rate of the IEEE802.3 standards for data center applications but also to initiate the unification of data format for wired and wireless network coverage. To date, the highest allowable data rates of the single-VCSEL-based optical link are 80 Gbit/s for the NRZ-OOK format under back-to-back (BtB) transmission 168 Gbit/s for the PAM-4 format over 150-m OM5 MMF, and the 224 Gbit/s for the QAM-OFDM format at BtB case. For the high-level complex data-format transmission with rigorous demand on the signal-to-noise ratio (SNR), this work demonstrates the most up-to-date 32-ray quadrature amplitude modulation generalized frequency division multiplexing (32-QAM GFDM) data algorithm with optimized amplitude and K value for encoding the multimode (MM) VCSEL. To achieve the higher spectral-usage efficiency based on the SNR spectrum for maximal transmission data rate, the bit-loading discrete multi-tone (DMT) technique is implemented by rearranging each subcarrier to the appropriate QAM levels. By utilizing 32-QAM GFDM and bit-loading DMT, the maximal data rate in the BtB case could respectively achieve 119.5 Gbit/s and 130 Gbit/s when operating the MM VCSEL at 55 °C. The transmission capacity of the VCSEL operated at 55 °C would decrease to 93.8 Gbit/s for 32-QAM GFDM and 83 Gbit/s for bit-loading DMT after propagating through OM5 MMF with modal dispersion.

Very-long-baseline interferometry (VLBI) is a type of astronomical interferometry used in radio astronomy. VLBI digital backend is a wideband data acquisition system with dedicated real time data processing algorithms implemented and installed in each VLBI station. The VLBI institutes in American, Europe, Japan and China have start to develop VLBI digital backends in 2000s. The first VLBI digital backend named Chinese VLBI Data Acquisition System (CDAS) developed by Shanghai Astronomical Observatory (SHAO) was finished in 2009. It has four intermediate frequency (IF) input channels with 512 MHz bandwidth for each. After processing, the output data rate is up to about 2048 Mbps. CDAS has begun to serve for Chinese Lunar Project in Chinese VLBI Network (CVN) stations in 2010. Since 2013, another type of VLBI digital backend has been designed in order to meet the requirement of VLBI Global Observation System (VGOS), it was named CDAS2. Comparing with CDAS, CDAS2 not only doubles the number of input channels but also makes the 10-Gigabit Ethernet (10GE) interface available. Due to the different algorithms implemented, the output data rate of CDAS2 is up to about 16384 Mbps. It will be installed in Sheshan VGOS station this year. Furthermore, CDAS3 has been put on the schedule. It will double the bandwidth of each IF channel and the maximum data rate of output, comparing with CDAS2. It is prepared for the next stage of VGOS, which need 1024 MHz bandwidth input for each channel and 32768 Mbps maximum data rate output. In this article, we will introduce these digital backends in detail including the hardware and algorithm. And also comparisons will be made.

We investigate and compare two radio resource management (RRM) approaches for a reliable Device to Device (D2D) enabled cellular network in an industrial environment. The D2D links have target Quality of Service (QoS) requirements in terms of minimum reliability and data rate while cellular users have minimum throughput requirements. The aim is to maximise the overall system throughput while ensuring the minimum (QoS) requirements are met. Interference is managed by jointly considering admission and power control based on interdistances between devices. The deferred acceptance (DA) game theoretic algorithm is used to perform matching and compared to a centralised optimisation approach. Numerical simulations are used to verify the performances of the two algorithms.

Pattern division multiple access (PDMA) is a multi- carrier non-orthogonal multiple access (NOMA), which can meet the requirements of massive user connections and super-high data rate in the fifth generation (5G) wireless networks. In this paper, we work on the optimization of power allocation to improve the performance in the down-link PDMA system with imperfect channel state information (CSI) at transmitter. The outage throughput of the system is maximized by optimizing the power allocation under the constraints of maximum transmits power, minimum user data rate, and outage probability. Since this optimization problem is a probabilistic mixing problem, we first turn it into a non-probability problem. Then, assuming the pattern matrix is known, we propose an iterative power allocation scheme. The closed-form expression of power allocation is derived based on Karush-Kuhn-Tucker (KKT) conditions. The simulation results demonstrate that the proposed iterative power allocation scheme yields better performance over the existing schemes.

In recent years, the growth of smart phone industry drives its users to demand better quality multimedia services while achieving faster internet speeds. With a higher number of subscribers and more data hungry applications, there is a need to improve the current 3G HSDPA data rate until the 4G network is fully implemented globally. Therefore, the aim of this thesis is to improve the downlink data rate of the HSDPA system throughput through both transmitter and receiver optimisations while balancing the complexities of the optimisation algorithms. Initially, improving system throughput through power allocation strategies is investigated in this thesis. Current schemes proposed in the literature that use Equal SINR Equal Rate (ESER) allocation can improve the system throughput for single rate allocation but require a rather high complexity. In this thesis, a System Value (SV) criterion is proposed to decrease the traditional ESER allocation method while achieving similar system throughput performance. To further increase the system throughput, a Successive Interference Cancellation (SIC) receiver is proposed which not only improves the data rate but also has a reduced complexity. The proposed SIC receiver can be used in conjunction with both ESER allocation schemes as well as equal energy allocation schemes. Another transmitter optimisation strategy is to improve the signature sequences. A signature sequence design that minimises correlations between the sequences while reducing the Inter-Symbol Interference (ISI) and noise is proposed. To reduce the amount of channel state information required, a signature sequence selection method which removes the signature sequences that are heavily a ected by interference is also proposed. The proposed optimisation strategies have been veri ed through MATLAB simulations. Moreover, practical measurements using the National Instruments (NI)-PXIe testbed have been carried out for the proposed SIC algorithm which further con rm its e ectiveness in a real world environment.

The expanding capacity of today's memory cards and increasing speed of processors have created demands for high data rate interfaces between memory cards and processors. Compared to conventional contact pins, wireless interfaces have received tremendous interest for reasons of more convenience, higher reliability, and higher data rate. Two major types of near-field wireless communication techniques using capacitive coupling and inductive coupling channels have been investigated. Tens of Gb/s/ch is achieved using both methods with a communication distance of tens of microns in TCI (thru-chip-interface) applications [1–2]. However, when the communication distance denters the mm range in such applications as non-contact memory cards, the sizes of capacitors or inductors must be up scaled to detect enough electrical flux or magnetic flux, whose magnitude decay as 1/dn (n>1). As a result, the self-resonance frequency f SR is reduced significantly, which becomes the dominant limiting factor for the achievable data rate, since the maximum data rate is usually chosen as 1/2 or 1/3 of f SR in order to avoid signal peaking [3]. Although multi-channel solutions are viable to increase the total data rate, complex systems are required to address the skew issues in synchronization, and low area efficiency is resulted to reduce crosstalk interferences as shown in Fig. 28.3.1.

The data rate of the dynamic random access memory (DRAM) interface has been greatly increased to reduce the performance gap between the DRAM and the central processing unit (CPU). The data rate of double-data rate (DDR) synchronous DRAM (SDRAM) is now exceeding 266 Mb/s/pin while the packet-based RAMBUS DRAM is offering up to 1066 Mb/s/pin data rate. The difference in the data rate is mainly due to their different channel structures. These DRAM interface channels are basically multi-drop bus where a driver should drive multiple loads. The maximum data rate is determined by how the multiple loads are configured. The data rate of the DRAM interface channel has been greatly increased and is expected to exceed 2 Gb/s/pin in the near future. To achieve this goal, the physical interface such as the bus structure should be optimized to minimize the timing uncertainty. The I/O timing circuitry plays an important role in determining the maximum data rate. Thus, the, circuit design should also be focused on minimizing timing uncertainty.

The application of unmanned aerial vehicles (UAV) as base station (BS) is gaining popularity. In this paper, we consider maximization of the overall data rate by intelligent deployment of UAV BS in the downlink of a cellular system. We investigate a reinforcement learning (RL)-aided approach to optimize the position of flying BSs mounted on board UAVs to support a macro BS (MBS). We propose an algorithm to avoid collision between multiple UAVs undergoing exploratory movements and to restrict UAV BSs movement within a predefined area. Q-learning technique is used to optimize UAV BS position, where the reward is equal to sum of user equipment (UE) data rates. We consider a framework where the UAV BSs carry out exploratory movements in the beginning and exploitary movements in later stages to maximize the overall data rate. Our results show that a cellular system with three UAV BSs and one MBS serving 72 UE reaches 69.2% of the best possible data rate, which is identified by brute force search. Finally, the RL algorithm is compared with a K-means algorithm to study the need of accurate UE locations. Our results show that the RL algorithm outperforms the K-means clustering algorithm when the measure of imperfection is higher. The proposed algorithm can be made use of by a practical MBS–UAV BSs–UEs system to provide protection to UAV BSs while maximizing data rate.

Due to its high speed and low latency, D2D communication plays an important role in providing proximity data services in 5G systems, which may contain privacy sensitive data. Covert communication is useful to protect the privacy of user data against adversaries. In a D2D underlaying cellular network, an antenna array can be used at a base station (BS) to transmit artificial noise to confuse adversaries that try to detect D2D covert signals. Based on the numbers of antennas at BS, two covert schemes are presented in this work and their performances are evaluated in terms of D2D covert throughput, i.e., maximum achievable D2D data rate with the given covertness requirements. As only channel distribution information (CDI) of adversary links is known to the BS, the average minimum error probability (AMEP) is used as a metric to measure the covertness performance. In the proposed schemes, closed-form expressions of the minimum AMEP and achievable D2D data rate are derived. It is shown that the derivation of minimum AMEP can be simplified if either one or massive antennas are allocated for sending artificial noise. The analytical results are compared to Monte-Carlo simulation results to verify the feasibility of the proposed schemes. It is also revealed that covert throughput can be further improved by setting system parameters properly, e.g., the number of antennas at BS and artificial noise transmit power.