CDMA means all depedancy on power control here i write on Power Control Inaccuracy in cdma. Traffic capacity of CDMA systems is increased by implementing an appropriate power control scheme to equalize the performance of all subscribers in the system. The appropriate power control scheme reduces the interference to the other adjacent cells. The less … Read more
The Reverse CDMA Channel is composed of Access Channels and Reverse Traffic Channels. These channels share the same CDMA frequency assignment. Each Traffic Channel is identified by a distinct user long code sequence and each Access Channel is identified by a distinct Access Channel long code sequence. The following figure shows as example of the … Read more
Implement security through encryption (both control plane (RRC) data and user plane data) and integrity protection (for control plane (RRC) data only), it is the responsibility PDCP layer. A PDCP Data PDU counter (known as the “COUNT” into the specifications of LTE) is used as an input to algorithms security. value COUNT is incremented for … Read more
Cell selection consists of the UE seeking stronger cell on all supported frequencies of each transport supported rat until it finds a suitable cell. The main requirement for cell selection is that it should not take too much time that becomes more difficult with the growing number of frequencies and rats to be searched. The … Read more
Depending on the type of measurement, the UE can measure and report any of the following: serving cell; list of cells (e.g., cells shown as part of the object of measurement); cells are found at the frequency set (ie cells are the cells that are not listed, but found UE). For some rats, the UE … Read more
Here I write some small notes on connection Re-Establishment procedure in LTE. In a number of cases of failure (eg failure of radio link failure of teaching RLC unrecoverable error, failure of compliance reconfiguration), the procedure for restoring EU RRC connection, provided that security is active. If security is not enabled, when one of the … Read more
Effect of Interleaving In GSM the speech frame is transmitted over eight consecutive bursts. The fast fading causes bursty bit errors that degrade the efficiency of the convolutional coding. The interleaving is designed to spread these errors over longer time. However, the decoding performance is not significantly improved if consecutive bursts are exposed to the … Read more
To protect the logical channels from transmission errors introduced by the radio path, many different coding schemes are used. The diagram below illustrates the coding process for speech, control and data channels; the sequence is very complex. The coding and interleaving schemes depend on the type of logical channel to be encoded. All logical channels … Read more
To Improve Error Protection and Security of Data the Data is Interleaved and its type is Diagonal let’s check how it works. The diagram below illustrates, in a simplified form, diagonal interleaving applied to a 9.6 kbit/s data channel. The diagram shows a sequence of ‘data blocks’ after the encoding process previously described, all from … Read more
As All Channel Interleaving in GSM but control channel is some different interleaved its interleaving rectangular lets understand how it. The diagram below illustrates, in a simplified form, the principle of rectangular interleaving. This is applied to most control channels. The diagram shows a sequence of ‘control blocks’ after the encoding process. Each block contains … Read more