UPLINK AND DOWNLINK IN LTE PORTABLE
The performance improvement will be done by varying the roll-off factor of the raised-cosine filter for pulse shaping after IFFT. A two-way radio system that has a 250-watt transmitter talking to 5-watt portable subscriber units truly will be lopsided in the downlink path.
Thus in this paper, the effect of pulse shaping on the performance of the uplink PAPR of distributed FDMA and localized FDMA will be dealt deeply. The dire consequence of the peak amplitudes generated by the superposition of several subcarriers of identical phases led 3GPP to adopt SC-FDMA as an uplink multiple access method. UPLINK AND DOWNLINK COMMUNICATION IN LTE In LTE, the OFDMA is used as downlink and SCFDMA as uplink modulation schemes with OFDM as the basic building block. LTE (E-UTRA) Frequency Bands 9, 1749.9-1784.9, 1844.9-1879.9 10, 1710-1770, 2110-2170 11, 1427.9-1447.9, 1475.9-1495.9 12, 699-716, 729-746. The idea to use OFDMA in the LTE uplink communications invoked discord among the members of the 3GPP standardization body because of the growing concern over the signal peakiness which degrades the efficiency of mobile station power battery consumption. Unlike the IEEE802.16m WiMAX which uses OFDMA in both downlink and uplink multiple access schemes, LTE and its advanced version systems continue to use different multiple access transmissions in which OFDMA and SC-FDMA are supported in the downlink and the uplink, respectively. Pre-commercial deployments have proved that LTE-Advanced will ensure the competitiveness of the 4G mobile networks by providing a high-data-rate, low latency and optimized system. LTE-Advanced is one of the most competing and widely adopted families of standards that will meet the 4G broadband wireless mobile communications requirements recommended by the IMT-Advanced for the terrestrial radio interface specifications. 1 and 8 describes downlink and uplink fixed reference channels, respectively, which may be used for modeling any modulation and coding scheme (MCS) index in. Typically, the maximum allowed downlink transmission power in cellular systems is 43 dBm, while the uplink transmission power is limited to around 24 dBm. On the other hand, in the case of time division duplex (TDD) version of LTE, the same frequency range is used and an uplink-downlink configuration defines how the time slots are allocated for.
0 kommentar(er)
