Dynamic spectrum management (DSM) is an important technique for mitigating crosstalk noise in multi-user digital subscriber line (DSL) environments. Until now, most of the proposed algorithms DSM have been designed solely purpose bitrate maximization. These assume a fixed maximum total power and neglect energy consumption DSL modems. However, since recently there strong interest field to reduce as shown, e.g., by European Commissions¿ code conduct on broadband equipment. In contrast...

We present a new approach to identify the parameters of given digital predistortion (DPD) structure for power amplifier (PA) linearization. Traditional methods optimize single objective, typically time-domain mean squared error. propose use multi-objective optimization algorithm jointly in-band and out-of-band performance as quantified by respective metrics defined in particular communication standard. Our constrained allows checking standard-compliance at time DPD identification....

We consider a constrained multi-carrier power allocation problem in interference-limited multi-user systems with finite set of transmission rates. The Lagrange relaxation is common technique for decomposing such problems into independently solvable per-subcarrier problems. Deviating from this approach our main contribution the proposal novel spectrum management framework based on Nonlinear Dantzig-Wolfe decomposition. It allows suboptimal initialization and methods low complexity. While we...

G.fast is the next-generation digital subscriber line (DSL) technology targeting bit-rates of up to 1 Gbps. Very high speed 2 (VDSL2) latest DSL delivering 100 Mbps. Replacement VDSL2 by modems will be gradual, which implies coexistence these two systems. and use different symbol durations, carrier frequency spacings, sampling rates, results in inter-carrier inter-symbol interference (ICSI). We derive an analytical model ICSI capturing differences modulation. Furthermore, through simulations...

A multi-user signal coordination scheme known as Vectoring will play a crucial role in next generation digital subscriber lines (DSL). Previous studies have demonstrated that vectoring increases the bitrate of DSL systems due to its ability mitigate interference. In this work we show how improves energy-efficiency over state-of-the-art spectrum balancing methods. addition investigate impact channel-state information errors and low-complexity implementations on performance Vectoring. We find...

In recent years an increasing effort was made to reduce the energy consumption in digital subscriber line equipment. Dynamic spectrum management (DSM) has been identified as one promising method achieve energy-efficiency discrete multitone based systems. An open research question is how ensure system robustness when applying highly optimized energy-efficient management. this paper, we study problem of uncertainty crosstalk noise and parameters, knowledge which indispensable for many DSM...

We apply constrained optimization techniques to optimally allocate the bandwidth and power users in a cellular network. investigate partial frequency reuse with multiple full regions for inter-cell interference mitigation. show that non-convex sum-rate maximization problem becomes convex under certain simplifying assumptions. Moreover, an efficient algorithm is developed solve fixed allocation. The optimal solution assigns all available users. Finally, we prove even without simplifications...

In this paper we apply constrained optimization techniques to optimally allocate bandwidth and transmit power the users in a cellular network. We utilize partial frequency reuse with one user full regions as inter-cell interference mitigation technique. show that non-convex sum-rate maximization problem becomes convex under some simplifying assumptions. Moreover, an efficient algorithm is used solve for fixed allocation. Our results optimum, amount of assigned users. further demonstrate by...

The use of a cyclic prefix (CP) in orthogonal frequency-division multiplexing (OFDM) allows to avoid inter-carrier interference (ICI), but also diminishes the efficiency modulation scheme. We study problem jointly optimizing CP length and discrete bit power-loading under ICI OFDM, exemplified by its application power line communication (PLC). derive low-complexity linear programming (LP) based performance upper-bound which is applicable analyze suboptimality bit-loading heuristics varying...

The large number of broadband users and its forecast growth has recently triggered research on energy-efficiency in digital subscriber lines (DSLs). A promising technique are low-power modes (LPMs) as standardized asymmetric DSL 2 (ADSL2) which let the connection operate downstream direction with reduced transmit rate power. We study problem optimizing LPM rate-level for energy-efficiency. traffic-independent setting is proposed based an analytical competitive framework. Also, a Markov chain...

Optimization of the power spectrum alleviates crosstalk noise in digital subscriber lines (DSL) and thereby reduces their consumption at present. In order to truly assess DSL system consumption, this article presents realistic line driver (LD) models. These are applicable any extend previous models by parameterizing various circuit-level non-idealities. Based on model a class-AB LD we analyze multi-user optimization problem propose novel algorithms for its global or approximate solution. The...

Low-power modes (LPM) are a standardized means in asymmetric digital subscriber lines (ADSL) 2 for reducing the power consumption at central office. However, activation of LPMs is hampered by operators' concern instability introduced frequent transmit changes. The injection artificial noise (AN) has been proposed as standard-compliant stabilization technique. We develop an analytical solution setting AN spectrum. Based on this we jointly optimize spectrum and signal-to-noise ratio (SNR)...

Inter-carrier interference (ICI) in multicarrier systems results a coupling among all subcarriers. This greatly complicates the problem of multiuser bit and power allocation, also referred to as spectrum balancing. We propose Lagrange relaxation ICI terms, an optimal algorithm for solving resulting relaxed balancing problem. While this gives us rate-performance upper bound, based on it we novel heuristic computing lower bound. The is exemplarily applied digital subscriber lines (DSL) with...

Cooperation of transceivers on signal level at the remote terminal-often referred to as vectoring-is an effective approach mitigate crosstalk in wireline transmission systems. While gain bitrate compared crosstalk-limited is substantial, initialization a vectoring system requires time and care ensure stability. In this contribution, fast scheme for vectored systems based spectral protection analyzed. Two scenarios are considered, where first one no prior channel information available, second...

In the near future, digital subscriber line (DSL) network operators will start deploying G.fast technology to stay competitive in broadband market. provides data rates of up 1 Gbps, which is a 10× higher rate than offered by widely deployed very high speed DSL 2 (VDSL2) technology. this paper we propose novel algorithm prequalify existing VDSL2 customers for services. Motivated testbed and field trial results also new loop attenuation parameter prequalification purposes, namely geometric...

Spectrum balancing is an established optimization approach in multi-carrier digital subscriber line (DSL) systems. It has previously been applied to very different performance objectives such as sum-rate, min-rate, or fairness maximization and sum-power minimization. In this work we study the of service coverage, which will be defined number DSL lines can granted operator-specified high-bandwidth service. The proposed algorithm based on a described mathematical decomposition framework. We...

The reduction of energy consumption in digital subscriber line (DSL) networks has obtained considerable attention recently. Today's DSL is designed under an ldquoalways onrdquo principle to keep the crosstalk noise as stable possible. Departuring from this restriction, one approach achieve savings by ldquolazy schedulingrdquo which exploits tradeoff between energy-consumption and transmission delay inherent many communication systems. This work extends scope idea multi-user interference...

We study the multi-user and multi-carrier power allocation (spectrum balancing) problem in digital subscriber line (DSL) networks under inter-carrier inter-user interference as well self-interference. The key assumption of this work is that we do not have knowledge coefficients, but only access to total per-line noise power. Furthermore, lines may support different technologies or be part linear crosstalk cancellation (Vectoring) groups, which implies coupling among through per-transceiver...

We propose a generic method for handling coupling among subsystems in large-scale multiobjective analog circuit synthesis. It is based on sequentially solving optimization problems each subsystem. The approach exemplified pure feasibility problem of black-box passive filter design communications application. A proof-of-concept the proposed provided through simulation. practical outcome well-selected set alternative choices that all fulfill pre-specified constraints.

Multiuser interference, i.e., crosstalk, is the main bottleneck for digital subscriber lines (DSL) technology. Dynamic spectrum management (DSM) mitigates crosstalk by focusing on multiuser power/frequency resource allocation problem, and it can provide formidable gains in performance. In this paper, we look at DSM problem from a different perspective. We formulate with power vectors defined spherical coordinates, as function of radius angles. see that reformulation permits us to exploit...

Vectoring very high speed digital subscriber line 2 (VDSL2) lines will coexist with legacy VDSL2 during copper access network migration. Without the ability of to cooperate for crosstalk channel estimation, may still suffer from noise. We study spectral protection by dynamic upstream power back-off (UPBO) and provide a multiobjective methodology fairness optimization between lines. Extensive simulation exemplary testbed results up 20 illustrate tradeoff in mean-rate offered operators, as...