The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In this paper, a low-complexity sparse channel estimation scheme is proposed for massive three dimensional multi-input multi-output (3D-MIMO) systems. In outdoor propagation environment, 3D-MIMO channels exhibit joint sparseness in both temporal and angular domains, sharing the common support in delay domain. By taking prior knowledge of the structured sparseness, the proposed heuristic channel estimation...
This paper investigates the beamforming for three- dimensional multiple input multiple output (3D-MIMO) systems with inaccurate channel state information (CSI). From the view of angle-domain, the 3D-MIMO channel is sparse on the high 3D resolution provided by planar antenna array with large number of antenna elements at the base station (BS) in 3D-MIMO systems. Prior knowledge of sparsity is not only...
Channel prediction is an appealing technique to mitigate the performance degradation due to the inevitable feedback delay of the channel state information (CSI) in modern wireless systems. We first propose a general MIMO-OFDM channel prediction framework, which exploits both the spatial and temporal correlations among antennas. Then we derive two predictors which select data for auto-regressive (AR)...
Identifiability is a fundamental issue in blind signal processing. It is well known that there are two types of inherent ambiguities: the scalar and permutation ambiguities. However, this is obtained under the condition that no a priori information of input signals is assumed. We show that if the information of source constellation is exploited, with a general constellation, there is an inherent discrete...
Blind channel estimation is a promising technique to reduce the pilot overhead. Unfortunately, most existing algorithms suffer from the scalar ambiguity problem, and hence only achieve semi-blind identification. In this paper, we show that with the information of source constellation, the phase of the ambiguous scalar can be divided into a fractional part and an integer part. Then we propose a multiple-constellation...
In this paper, a sampling based channel estimation as well as an iterative particle filter (PF) signal detection scheme for fast flat fading multiple-input multiple-output (MIMO) channels is proposed, which aims at achieving the required bit error rate (BER) performance under the scenario that the accurate channel estimation is difficult to attain. The channel estimation is comprised of two parts:...
In 802.11 infrastructure BSS, the channel throughput will decrease when increasing the number of competing STAs. Also severe asymmetry exists between downlink and uplink data because AP accesses the share channel without any priority. Both problems are solved by a new MAC schema which adjusts the initial contention window of AP and STA to optimized values. A new estimation method for STA number is...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.