Random Access Procedure in UMTS In This article I write about step of Physical random access procedure in umts. As shown in below figure steps is as below. Derive the available uplink access slots, in the next full access slot set, for the set of available UMTS RACH sub-channels within the given ASC. Randomly select … Read more
Diversity Reception: Multiple Antennas at Base Station Each Antenna is Affected by Multipath Differently Due to Their Different Location Allows Selection of the Signal Least Affected by Multipath Fading If Diversity Antennas are Good, Why Not Use Base Stations as a Diversity Network? – Soft Handoff The concept of diversity reception has been well known … Read more
Time diversity is a technique common to most digital transmission systems. The Rake Receiver is used to find and demodulate multipath signals that are time delayed from the main signal. Rake Receiver to Find and Demodulate Multipath Signals. Data is Interleaved : Spreads Adjacent Data in time to Improve Error Correction Efficiency Convolutional Encoding : … Read more
We know that we normally have several independent paths from TX to Rx of different lengths, these are affected and delayed differently, Signals that start out together at the transmitter will be separated in time when they reach the receiver Diversity doesn’t work with Line of Sight, This is exploiting Multipath rather than fighting it … Read more
Here I write down on How Time Slot Allocation for Uplink and Downlink LTE and How Cyclical Prefix Allocation for LTE Time Slot Allocation for Uplink and Downlink – TDD specific The time division nature of LTE TDD will also require radio engineers to consider how time slots are shared between uplink and downlink based … Read more