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.
Reduced-complexity implementations are critical for massive MIMO (Multiple Input, Multiple Output) systems. In this paper we consider the uplink of broadband massive MIMO systems employing SC-FDE (Single-Carrier with Frequency-Domain Equalization) schemes, where multiple users transmit to a single base station with a large number of antennas. We propose low-complexity frequency-domain detection schemes...
It is well known that Massive MIMO systems (Multiple-input multiple-output) have high potential for future wireless broadband systems. However, high spectral and power efficiency requirements can be only achieved by multilevel modulations and efficient power amplification. This seems contradictory, due envelope variation of multilevel constellations that can compromise efficiency of power amplification...
Nowadays, the demand of high data wireless transfer rates is growing with the big and fast grow of smart phones. As a consequence, the spectrum is getting overloaded with communications, increasing the interference. Therefore a different path of ideas has been followed and the communication process has been taken to the next level by the usage of big arrays of antennas and multi-stream communication...
The combination of massive multiple input multiple output (MIMO) schemes with orthogonal frequency division multiplexing (OFDM) modulations are being considered for 5th generation (5G) wireless broadband systems. However, both the high complexity associated to massive MIMO transceivers as well as the amplification problems of OFDM constitute important drawbacks of such combination. In this paper we...
Multiple input multiple output (MIMO) schemes combined with orthogonal frequency division multiplexing (OFDM) modulations are widely employed in broadband wireless systems. However, the transmitted signals are prone to nonlinear distortion effects due to their high envelope fluctuations. In this paper, we present a simple analytical method for studying nonlinear effects in MIMO-OFDM systems. Our method...
Mobile communication systems must support multiple users achieving at same time privacy. Thus security is a crucial requirement to assure privacy of the data transmitted from and for each user. Several solutions can be adopted to implement security. Commonly they are based on encrypted algorithms implemented by higher layers, such as private and public encrypted keys. Also security can be implemented...
We consider signal space diversity based on Complex Rotation Matrices (CRM) known to provide good performance gains over uncorrelated Rayleigh fading channels. OFDM/OFDMA signals based on LTE-A parameters are combined with CRM, spatial multiplexing (MIMO), Turbo or LDPC codes. It is shown that CRM outperform RRM (Real Rotation Matrix), as well as HM (Hadamard Matrices). The gains are especially high...
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.