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Recent works on the future 5G cellular communication proposed that the enormous raw bandwidth availability of the millimeter-wave (mmWave) frequencies is an excellent opportunity to increase data capacity and channel capacity. However, mmWave transmission requires beamforming to overcome the high path loss, as well as other losses due to rain and oxygen absorption and higher noise floor associated...
Achieving the promising gains of massive multiple- input multiple-output (MIMO) relies on accurate channel state information. In this paper, results from detailed time-dynamic system simulations of reciprocity based massive MIMO systems in the 3GPP 3D scenarios are presented. Downlink (DL) multi- user MIMO performance is found to be sensitive to errors in channel estimates obtained from uplink (UL)...
Multiple-antenna systems have been shown to provide significant performance improvements over single-antenna systems. Theoretical analysis, simulation and experimental testing corroborate improvements in capacity and transmit power/energy savings. Unfortunately, co-located MIMO radios have numerous disadvantages compared to single-antenna radios; such as more complex RF and modem signal processing,...
From a cross-layer perspective in distributed antenna systems, system throughput coefficient and fairness coefficient are defined taking into consideration both queue state information in data-link layer and channel state information in physical layer. Particularly, a self organizing map based optimization (SOMO) algorithm is proposed to solve the proposed optimization problem. Through simulations,...
We present high data rate wideband transceiver design and experimental evaluation for 3.62 Gbps wireless transmission systems in this paper. The present system provides high definition moving picture and contents in a real-time wireless environment at home, offices or class rooms of universities. Also, the present platform provides a test platform for the Giga level high throughput wireless communication...
The radio resource management functionality plays an important role in new OFDMA based networks. The control of the network resource division among the users is performed by packet scheduling functionality based on maximizing cell coverage and capacity while satisfying certain quality of service constrains. In order to mitigate inter-cell and co-channel interference problems in OFDMA cellular networks,...
Conventional zero-forcing precoding was well investigated, but it hadn't considered the channel quality indicator (CQI) mismatch for practical system with limited feedback. This paper studies a novel zero-forcing precoding with channel quality indicator (CQI) estimation and adjusting, channel directional information(CDI) quantization, user scheduling and link adaptation and then proposes a CQI estimation...
A cross-layer power allocation scheme for distributed antenna systems is proposed in this paper. From a cross-layer perspective, system throughput coefficient and fairness coefficient are defined taking into consideration both queue state information in data-link layer and channel state information in physical layer. Particularly, an improved particle swarm based optimization algorithm is proposed...
In this paper, new dynamic resource allocation algorithms are presented for the downlink of multi-user MIMO-OFDMA/SDMA systems. Since it is difficult to obtain the optimal solution to the joint optimization problem, the whole procedure is divided into two steps, namely, the subcarrier-user scheduling and the resource allocation. In the first step, a new metric is proposed to measure the spatial compatibility...
In this paper we report our works on designing MIMO wireless LAN system with throughput 600 Mbps for 30 meter propagation range by using Generalized Layered Space Time (GLST) coding and its implementation on field programmable gate array (FPGA) chips. At the receiver we employ our low-complexity GLST decoder to maintain error performance with low computational complexity. A novel packet format is...
We consider a multiuser MIMO-OFDM downlink system with single antenna mobile terminals (MTs) where channel state information at the base station is provided through limited uplink feedback (FB). In order to reduce the FB rate and signal processing complexity, the available bandwidth is divided into resource blocks (RBs) whose number of subcarriers reflects the coherence bandwidth of the channel. This...
Proportional fair scheduling (PFS) provides good balance between throughput and fairness via multi-user diversity and game-theoretic equilibrium. Very little analytical work exists on understanding the performance of PFS. Moreover, most researches on PFS are for cellular networks and typically use linear rate model or logarithm rate model to simplify the theoretical analysis of PFS. Since the linear...
Standardization work is nearly complete on long term evolution (LTE) of the UMTS Terrestrial Radio Access and Radio Access Network which is aimed for commercial deployment in 2010. Goals for the evolved system include support for improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operations and seamless integration...
Orthogonal Frequency-Division Multiplexing is a multi-carrier modulation scheme, where information symbols are transmitted in parallel over the channel by using a set of subcarriers. One of the main advantages is increased robustness against frequency selective fading and narrowband interference. In this paper we study the performance of two dual-codeword Single-User Multiple-Input Multiple-Output...
Traditional non-linear (dirty paper coding) and linear (beamforming) preceding techniques that maximize the sum rate in the multi-antenna broadcast channel often suffer severe performance degradation when the channel state information (CSI) at the transmitter is erroneous or outdated. This has motivated the recent development of a linear preceding algorithm that uses the channel distribution information...
In this paper, multiple antenna based intercell interference mitigation techniques are studied in the downlink of an OFDM-based cellular radio network. At the base stations, multiple antennas are used for transmit beamforming in order to reduce the intercell interference spatially spread in the network. At the user terminals, multiple receive antennas facilitate implementation of interference rejecting...
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