Eb/No corresponds to energy per bit over interference plus noise density for a given target FER (typical FER target is 1%). In digital communications, it is customary to designate one-sided noise density with No. In CDMA, interference is dominated by the noise generated due to other users in the system. Here No, is refers to … Read more
Soft handoff is the term that is normally associated with the fact that a CDMA system makes a connection to a target cell prior to releasing (breaking) from the source site, commonly referred to as “make-before-break”. A hard handoff, associated with AMPS, GSM, or USDC, requires that the signal strength from the target cell be … Read more
In determining RF coverage in CDMA systems, the effect of interference generated from the serving cell as well as the neighboring cells must be considered, this is in contrast to the RF coverage analysis for AMPS cells where interference mainly affects the frequency assignment but not the coverage. The interference margin is dependent upon the … Read more
There are various parameters and terms which come into play when discussing PN offsets and their function in CDMA. System Time All base station digital transmissions are referenced to a common CDMA system-wide time scale that uses the Global Positioning System (GPS) time scale, which is traceable to and synchronous with Universal Coordinated Time (UTC). … Read more
The design of a PN offset plan for CDMA is comparable to that of a signalling channel frequency plan in analog. The consequences of poor offset planning include the following: Active Set Pilot Interference – This phenomenon would occur in the active area and involve the active search window (SRCH_WIN_A). The interfering signal would need … Read more
Traffic Channel Definitions In analog systems, the traffic channels (or voice channels) are synonymous with the physical transceiver hardware. The nature of CDMA technology implies that the effective traffic carrying capacity of a CDMA carrier varies in accordance with the interference density in the band and also depends on various CDMA system parameters. From the … Read more
CDMA Handoff Defination,Types and Capacity Handoffs The TIA/EIA Interim Standard, Mobile Station – Base Station Compatibility Standard of Dual- Mode Wideband Spread Spectrum Cellular System (TIA/EIA/IS-95), states that a CDMA base station shall support three types of handoff processes. Which type of handoff used in cdma? CDMA to CDMA Hard Handoff A CDMA to CDMA … Read more
Three of India’s largest mobile networks have requested that a portion of the radio spectrum reserved for CDMA services be re purposed for use by the GSM networks. Bharti Airtel, Vodafone and Idea Cellular sent a joint letter to the Department of Telecoms. “We recommend that the 800 MHz spectrum band is harmonies with the international … 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
Here i write down on how Forward Channel works in CDMA ? and its Structure. The following figure shows an example of the code channels transmitted by a base station. Out of the 64 code channels available for use, the example depicts the Pilot Channel (always required), one Sync channel, seven Paging Channels (the maximum … Read more