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How Forward Link Traffic Channel Physical Layer in CDMA

Voice data at 9600 bps or 14400 bps (full rate) is first passed through a convolutional encoder, which doubles the data rate for the 9600 bps case or increases it by 1.33 times for the 14400 bps case. It is then interleaved, a process that has no effect on the rate, but does introduce time … Read more

How Forward Error Protection in CDMA

Uses Half-Rate Convolutional Encoder Outputs Two Bits of Encoded Data for Every Input Bit Unlike many digital cellular systems, CDMA provides powerful error correction to all voice data bits. This is desirable in CDMA since the idea is to increase the occupied bandwidth (spread the data). The forward link uses a half-rate convolutional encoder to … Read more

Sectorization Gain in CDMA

Sectorization gain can be somewhat of a misleading term. One could think of theĀ  sectorization gain as more of a reduction factor. For an omni site, the sectorization gain is one. With a sector site, one could initially try to multiply the resulting capacity of an omni site (or single sector) by the number of … Read more

Power Control Inaccuracy in CDMA

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

Conventional Blocking Analysis for CDMA

Conventional Blocking formula and its Analysis for cdma. In AMPS and TDMA systems, voice/traffic channels are assigned to users as long as they are available. Given the required offered traffic, the Erlang B model is used to determine the number of traffic channels required to provide a predetermined grade of service. The Erlang B model … Read more

Reverse Channel Structure in CDMA

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

How Inter-RAT Mobility performs in LTE

Here I write on How Inter-RAT Mobility performs in LTE, means Handover to LTE and Mobility from LTE. Handover to LTE Procedure for handover of LTE is largely the same as the handover procedure in LTE. The main difference is that the handover to LTE AS a whole-configuration must be signaled, and the LTE it … Read more