Benefits of SC-FDMA Receiver in LTE Low Peak-to-Average Power Ratio (PAPR): SC-FDMA (Single-Carrier Frequency Division Multiple Access) exhibits a lower PAPR compared to other modulation schemes, reducing the demand for power amplifiers with high linearity. Improved Power Efficiency: Lower PAPR contributes to improved power efficiency, making SC-FDMA well-suited for mobile devices with limited battery capacity. … Read more
What is main Difference between DL and UL in LTE ? OFDMA Advantages Robust against narrow-band co-channel interference Robust against Intersymbol interference (ISI) and fading High spectral efficiency Efficient implementation using FFT Drawbacks High Peak-to-Average Power Ratio The power limitation is more problematic in UL than in DL Signal with high PAPR will limit the … Read more
How OFDMA Transmitter in LTE ? In the downlink, OFDM is selected to efficiently meet E-UTRA performance requirements. With OFDM, it is straightforward to exploit frequency selectivity of the multi-path channel with lowcomplexity receivers. This allows frequency selective in addition to frequency diverse scheduling and one cell reuse of available bandwidth. Furthermore, due to its frequency domain … Read more
Cyclic Prefix problem in LTE The cyclic prefix (CP) in LTE is a guard interval inserted in the time domain between successive symbols or OFDM (Orthogonal Frequency Division Multiplexing) symbols. Its purpose is to mitigate the effects of multipath fading and inter-symbol interference by providing a guard time that allows the signals to settle before … Read more
Inter-Symbol Interference in LTE Definition: ISI is a phenomenon in LTE where symbols transmitted over a communication channel overlap, causing distortion in the received signal. Causes: Multipath Propagation: Signals take multiple paths with different delays, leading to overlapping symbols. Time Dispersion: Variation in signal arrival times at the receiver contributes to ISI. Impact on LTE: … Read more
LTE Sub-carrier How Many Sub Carrier in LTE? Read below,..There are different kinds of sub-carriers: Data sub-carrier Pilot Sub-carrier DC sub-carrier Guard Sub-carrier The result is intersymbol interference not only within a subcarrier but also between subcarriers. To prevent symbols from overlapping and to reduce the intersymbol. DC stands for Direct Current and it is … Read more
In FDM, the sub-carriers are separated in the frequency domain to avoid interference between the sub-channels It results in a loss of spectrum efficiency because the frequency guard band can not be used to send data.The OFDM allows one to remove the frequency guard band. Benefit: There are more sub-carriers, so more symbols are … Read more
OFDMA Principles in LTE Orthogonal Frequency Division Multiple Access (OFDMA) is a key technology used in Long-Term Evolution (LTE) to efficiently manage the transmission of data over the radio interface. Here’s an explanation of OFDMA principles in LTE: Frequency Division Multiplexing (FDM): OFDMA uses FDM to divide the available frequency spectrum into multiple subcarriers. Each … Read more
Constellation in LTE In LTE (Long-Term Evolution), the term “constellation” typically refers to the modulation scheme used for transmitting data over the air interface. LTE uses Quadrature Amplitude Modulation (QAM) to encode multiple bits into a single symbol. The constellation diagram visually represents how the amplitude and phase of the modulated signals correspond to specific … Read more
The 3G LTE uses 3 Quadrature Amplitude Modulations (QAMs) depending on the radio quality. QAM uses both the amplitude and the phase. LTE devices use QPSK, 16QAM and 64QAM to modulate data and control information. The eNodeB supports all of these modulation techniques for the downlink direction. However, 64QAM is optional in the uplink direction. … Read more