Search results
Results From The WOW.Com Content Network
Wireless LAN (WLAN) channels are frequently accessed using IEEE 802.11 protocols. The 802.11 standard provides several radio frequency bands for use in Wi-Fi communications, each divided into a multitude of channels numbered at 5 MHz spacing (except in the 45/60 GHz band, where they are 0.54/1.08/2.16 GHz apart) between the centre frequency of the channel.
As you can see from the table below, the FFI channels for BG1 and BG3 are 13-15 and 29-31, while the TFI channels for BG1 and BG3 are 9-12 and 25-28. As an example, Japan allows usage of 7392-7920 MHz, which is Band9, the highest frequency band in Band Group 3. This corresponds to Channel 31, also known as BG3 TFC 7.
When modeling spatial correlation it is useful to employ the Kronecker model, where the correlation between transmit antennas and receive antennas are assumed independent and separable. This model is reasonable when the main scattering appears close to the antenna arrays and has been validated by both outdoor and indoor measurements. [2] [3]
Zero-forcing (or null-steering) precoding is a method of spatial signal processing by which a multiple antenna transmitter can null the multiuser interference in a multi-user MIMO wireless communication system. [1]
Papers by Gerard J. Foschini and Michael J. Gans, [58] Foschini [59] and Emre Telatar [60] have shown that the channel capacity (a theoretical upper bound on system throughput) for a MIMO system is increased as the number of antennas is increased, proportional to the smaller of the number of transmit antennas and the number of receive antennas.
Long-range Wi-Fi is used for low-cost, unregulated point-to-point computer network connections, as an alternative to other fixed wireless, cellular networks or satellite Internet access. Wi-Fi networks have a range that's limited by the frequency, transmission power, antenna type, the location they're used in, and the environment. [ 1 ]
802.11 Beacon frame. A beacon frame is a type of management frame in IEEE 802.11 WLANs. It contains information about the network. Beacon frames are transmitted periodically; they serve to announce the presence of a wireless LAN and to provide a timing signal to synchronise communications with the devices using the network (the members of a service set).
It is difficult to design a single antenna to receive such a wide wavelength range, and there is an octave gap from 216 to 470 MHz between the VHF and UHF frequencies. So traditionally, separate antennas (outdoor antennas with separate sets of elements on a single support boom) have been used to receive the VHF and UHF channels. [6]