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Intuitively, the reason lies in the fact that where OFDM transmit symbols directly modulate multiple sub-carriers, SC-FDMA transmit symbols are first processed by an N-point DFT block. [9] In OFDM, as well as SC-FDMA, equalization is achieved on the receiver side, after the DFT calculation, by multiplying each Fourier coefficient by a complex ...
UMTS Terrestrial Radio Access Network (UTRAN) is a collective term for the network and equipment that connects mobile handsets to the public telephone network or the Internet. It contains the base stations, which are called Node B 's and Radio Network Controllers (RNCs) [ 1 ] which make up the Universal Mobile Telecommunications System (UMTS ...
Multi-carrier code-division multiple access (MC-CDMA) is a multiple access scheme used in OFDM-based telecommunication systems, allowing the system to support multiple users at the same time over same frequency band. MC-CDMA spreads each user symbol in the frequency domain.
The mobile transmits at the beginning of the time slot as received from the network. If the mobile is near the base station, the propagation delay is short and the initiation can succeed. If, however, the mobile phone is just less than 35 km from the base station, the delay will mean the mobile's transmission arrives at the end of the time slot.
Mobile architecture allows maintaining this connection whilst during transit. [1] Each day the number of mobile devices is increasing, mobile architecture is the pieces of technology needed to create a rich, connected user experience. Currently, there is a lack of uniform interoperability plans and implementation.
The first sub-block is the m-bit block of payload data. The second sub-block is n/2 parity bits for the payload data, computed using a recursive systematic convolutional code (RSC code). The third sub-block is n/2 parity bits for a known permutation of the payload data, again computed using an RSC code. Thus, two redundant but different sub ...
The main reasons for dropped calls in mobile networks are lack of radio coverage (either in the downlink or the uplink), radio interference between different subscribers, imperfections in the functioning of the network (such as failed handover or cell-reselection attempts), overload of the different elements of the network (such as cells), etc.
In cellular telephone communications, the air interface is the radio-frequency portion of the circuit between the cellular phone set or wireless modem (usually portable or mobile) and the active base station. As a subscriber moves from one cell to another in the system, the active base station changes periodically.