RF engineering is a trade off between: required radio spectrum (bandwidth), speed of data transmission (bit rates) and complexity of implementation. The pulse form used to modulate complex data symbols to the radio carrier frequency is the major element of this story. Over the years several pulse forms and their associated pulse shaping filters have … Read more
How Spreading & Dispreading in WCDMA-3G ? Traditional radio communication systems transmit data using the minimum bandwidth required to carry it as a narrowband signal. CDMA system mix their input data with a fast spreading sequence and transmit a wideband signal. The spreading sequence is independently regenerated at the receiver and mixed with the incoming … Read more
Spectrum efficiency DL : 3-4 times UL : 2-3 times Frequency Spectrum Scalable bandwidth : 1.4, 3, 5, 10, 15, 20MHz To cover all frequencies of IMT-2000: 450 MHz to 2.6 GHz Peak data rate DL : > 100Mb/s for 20MHz spectrum allocation UL : > 50Mb/s for 20MHz spectrum allocation Latency C-plane : < … Read more
LTE OFDMA and Downlink Frame Structure Details Downlink OFDMA time-frequency multiplexing LTE Spectrum Flexibility and Bandwidth FDD downlink frame structure detailed TDD frame structure LTE (any OFDM/OFDMA) band is made up of multiple small spaced channels and we call each of these small channels as “Sub Carrier”. Space between the chhanel and the next channel … Read more
Here I write LTE network first step. For LTE planning it is important to know what available spectrum bandwidth to operator is and what actual frequency band allocation. Understanding Operator Spectrum Bandwidth Availability The purpose of detail planning is to determine a solid radio network design for possible deployment so radio engineer should not be … Read more