Search results
Results from the WOW.Com Content Network
In telecommunications, the term cyclic prefix refers to the prefixing of a symbol with a repetition of the end. The receiver is typically configured to discard the cyclic prefix samples, but the cyclic prefix serves two purposes: It provides a guard interval to eliminate intersymbol interference from the previous symbol.
In wireless communication, the term numerology refers to "waveform parametrization, e.g., cyclic prefix, subcarrier spacing." [1] The waveform selection is subject to a set of real-world restrictions, so a practical mobile communication system (with signal propagation conditions that tend to vary significantly from one location to another), utilizes a set of different waveforms, or "multiple ...
For example, a low-complexity scheme referred to as WCP-OFDM (Weighted Cyclic Prefix Orthogonal Frequency-Division Multiplexing) consists of using short filters at the transmitter output in order to perform a potentially non-rectangular pulse shaping and a near perfect reconstruction using a single-tap per subcarrier equalization. [17]
After removing the cyclic prefix at the receiver, a DFT is applied to arrive in the frequency domain, where a simple single-carrier frequency-domain-equalization (SC-FDE) scheme can be employed, followed by the IDFT operation. DFT: Discrete Fourier Transform; IDFT: Inverse Discrete Fourier Transform; CP: Cyclic Prefix; PS: Pulse Shaping
Longer guard periods allow more distant echoes to be tolerated but reduce channel efficiency. For example, in DVB-T, guard intervals are available as 1/32, 1/16, 1/8 or 1/4 of a symbol period. The shortest interval (1/32) provides the lowest protection and the highest data rate; the longest interval (1/4) provides the highest protection but the ...
Some examples where Barker code is used are: pet and livestock tracking, bar code scanners, inventory management, vehicle, parcel, asset and equipment tracking, inventory control, cargo and supply chain logistics. [25] It is also used extensively for Intelligent Transport Systems (ITS) i.e. for vehicle guidance [26]
Two different lengths of the cyclic prefix are available to support different channel spreads due to the cell size and propagation environment. These are a normal cyclic prefix of 4.7 μs, and an extended cyclic prefix of 16.6 μs. LTE Resource Block in time and frequency domains: 12 subcarriers, 0.5 ms timeslot (normal cyclic prefix).
Multiple-input, multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) is the dominant air interface for 4G and 5G broadband wireless communications. It combines multiple-input, multiple-output technology, which multiplies capacity by transmitting different signals over multiple antennas, and orthogonal frequency-division multiplexing (OFDM), which divides a radio channel into ...