The air interface is the radio-based communication link between the mobile station and the active base station. LTE air interface supports high data rates. LTE uses Orthogonal Frequency Division Multiple Access (OFDMA) for downlink transmission to achieve high peak data rates in high spectrum bandwidth. LTE uses Single Carrier Frequency Division Multiple Access (SC-FDMA) for … Read more
The coding mode is called Regular Pulse Excited-Long Term Prediction (RPE-LTP). It works as follow: 8KHZ of sampling is performed first, then divided into frames with 20ms; every frame has 4 sub-frames; the duration of every sub-frame is 5ms; and the pure bit rate is 13kbit/s. The voice compression coding technique is widely used in … Read more
HS-PDSCH in WCDMA mainly for 2 works, Bearing service data and layer 2 overhead bits mapped from the transport channel SF=16, can be configured several channels to increase data service HS-PDSCH High-Speed Physical Downlink Shared Channel is a channel added to UMTS to increase downlink data rates. This is defined in Release 5 of the … Read more
Data bits modulate (modify) a carrier signal Basic modulation techniques: amplitude frequency phase. Data bits are represented over the transmission channel by SYMBOLS Symbol rate is expressed in Baud (Symbols per Second) Modulation of a carrier is used to transmit data bits efficiently over the air interface The modulation process creates modulation symbols. A modulation … Read more