Open loop power control together with optional power ramp-up is used during the random access process at the beginning of the connection until more accurate control information is available. Power loss due to transmission distance depends on to the increase of the distance between NodeB and the UE. In such a case, feedback information from another side is not … Read more
Here I write short notes on how to test open loop and close loop testing in lte and what idea behind it. In open loop no any data send back and in closed loop all relevant data available to both side lets check in some detail. Open and close loop testing in LTE: Open loop … Read more
The Open Loop Power Control require in cdma due to following reason. Assumes Loss is Similar on Forward paths and Reverse Paths Receive Power + Transmit Power = -73 All Powers in dBm Example: For a Received Power of -85 dBm Transmit Power = (-73) – (- 85) Transmit Power = +12 dBm Provides an … Read more
WDMA Air interface or Uu Interface contains 3 layers which describe as follow, The WCDMA layer 1 supports all functions required for the transmission of bit streams on the physical medium. It is also in charge of measurements function consisting in indicating to higher layers, for example, WCDMA Frame Error Rate (FER), WCDMA Signal to … Read more
UMTS Closed Loop Mode Transmit Diversity Used in DPCH and HS-PDSCH. The closed-loop-mode transmit diversity can only be applied to the UMTS downlink channel if there is an associated UMTS uplink channel. Thus this mode can only be used with UMTS dedicated channels. The chief operating principle of the closed loop mode is that the … Read more