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This paper proposes a transmit power and bit allocation algorithm with constraint on allocated bit number. Transmit power and bit allocation algorithms help improve performance of OFDM systems, however the existing algorithms can't fully satisfy the need of baseband data modulation methods, which only map a certain number of input bits into a data symbol. The presented approach aims at maximization...
Scalable video coding (SVC), together with adaptive modulation and coding (AMC), can improve wireless multicast streaming video by jointly performing radio resource allocation and modulation and coding scheme (MCS) selection. However, the existing schemes in the literature allocate radio resources for different video layers separately, which leads to a waste of radio resources. In this work, we introduce...
In this paper we propose a novel multicarrier (MC) architecture to address the energy saving problem in WLAN applications. We refer to this scheme as hybrid filtered multitone (H-FMT). Depending on the channel condition, H-FMT wisely switches between Filtered Multitone Modulation (FMT) with orthogonal pulses and adaptive orthogonal frequency division multiplexing (A-OFDM). We show that H-FMT provides...
Efficient Branch-and-Bound (BnB) based radio resource allocation (RRA) algorithms are proposed for Orthogonal Frequency Division Multiple Access (OFDMA) system in this paper. Optimal RRA solution can be obtained by BnB based Algorithm 1 with easy implementation. Suboptimal RRA solution can be achieved by BnB based Algorithm 2 with a large computational complexity reduction. Tradeoff between throughput...
It has been shown that multiuser MIMO systems have better capacity performance than single-user MIMO systems. For a large number of users, the transmitter selects a subset of users with good channels to maximize the system performance. Shannon capacity has been used most of the time as the performance measure for multiuser MIMO systems. In this paper, we consider BER as an alternative performance...
Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is a promising technology for high data rate transmission in wideband wireless systems for achieving high downlink capacities in future cellular systems. In this paper subcarrier and power allocation to each user at base-station is allocated to maximize the user data rates, subject to constraints on total power and...
In this paper, we propose a low complexity heuristic algorithm for radio resource allocation in orthogonal frequency division multiple access (OFDMA) systems based on subcarrier channel distribution information (CDI). We consider practical rate adaptation in which rate is adapted using a predefined set of modulation levels, which is in contrast to previous works that consider continuous rate. We formulate...
Multicarrier Modulation (MCM) is an attractive transmission technique that provides improved performance in various communication systems. A fundamental issue of multicarrier communication systems is power allocation, which is addressed as a constrained multivariable nonlinear optimization problem. In this paper, we develop a computationally efficient solution for the loading of multicarrier systems...
A bit and power allocation algorithm is proposed to maximizing the throughput given the total power and target bit error rate (BER). Because closed form expressions can be derived, the algorithm is of very low complexity, lower than the algorithms proposed by Krongold and Alexander. Furthermore the algorithm can achieve faster throughput than Krongold's and Alexander's algorithms.
Consider the problem of resource allocation on the downlink of a cellular OFDMA system. A fairness constraint is defined by a minimum data rate, a maximum bit-error rate and a maximum outage probability. This paper proposes a low-complexity resource allocation algorithm that requires a reduced feedback-overhead. Under a partial channel-state information, we derive the optimal subcarrier and power...
In this paper, a dynamic priority-based resource allocation (DPRA) scheme is proposed for uplinks in IEEE 802.16 wireless communication systems. The goal of the DPRA scheme is to maximize the system throughput while satisfying diverse QoS requirements. Four types of multimedia traffic are considered, where these multimedia traffic are given urgency degrees via dynamic priority values, and the radio...
This paper deals with our investigations into improving the performance of orthogonal frequency division multiple access (OFDMA) system with low computational complexity. In the proposed scheme, by taking attribute of a user channel like channel capacity decrease rate, subcarriers are allocated depending on the individual users' priority. This scheme is high reliable technique by ordering the capacity...
In this paper, we propose a robust STBC transmission scheme to combat the timing synchronization errors over frequency-selective multiple-access channels. First, the equivalent channel model in the presence of timing synchronization errors is derived and we find that the synchronization errors result in an equivalent channel model with larger number of correlated channel taps. Based on this correlated...
Algorithms for dynamic resource allocation in OFDM based wireless systems, known as Marge Adaptive optimization (MA), aim at reducing the total power consumption of the base station under individual minimum transmit rates for terminals. While it has been shown that using adaptive modulation increases the capacity of the wireless system, most MA algorithms may not be energy efficient when many mobile...
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