The state-of-the-art design of the LTE air interface is characterised by OFDMA (DL) and SC-FDMA (UL) together with MIMO. The downlink modulation is based on OFDMA (Orthogonal Frequency Division Multiple Access). OFDMA is a variant of OFDM which has the advantage that receiver complexity is at a reasonable level, it can handle scalable bandwidth requirements … Read more
The initial range is the process of estimating the distance or propagation time between a transmitter and a receiver. Area information can be used to assist in setting operating parameters for the transmitter and receiver. Since each MS has a unique distance from the base station, it is critical in the uplink to synchronize the … Read more
Sub-Carrier Allocation Mode 1 DL PUSC – Downlink partial Usage Sub-Channels The downlink PUSC replacement zone is unique, that must exist in the frame structure specified by the protocols. DL PUSC with all SC – PUSC with all sc indicates the PUSC replacement mode when all the bandwidth resources are used. DL FUSC- Downlink Full … Read more
There are major four channel in LTE Downlink trasport channel. which list below with its work in short. Paging Channel ( PCH) Supports UE discontinuous reception (DRX) to enable UE power saving. Broadcasts in the entire coverage area of the cell. Mapped to physical resources which can be used dynamically also for traffic/other control channels. … Read more
RACH(Random Access Channel) Uplink only. Used by the MS when making its first access to the Network. The reason for access could be initiation of a call or a page response. AGCH (Access Grant Channel) Downlink only. Used for acknowledgement of the access attempt sent on RACH. Used by the network to assign a signaling … Read more
Paging Control Channel(PCCH) A downlink channel that transfers paging information and system information change notifications. This channel isused for paging when the network does not know the location cell of the UE Broadcast Control Channel (BCCH) Provides system information to all mobile terminals connected to the eNodeB. A downlink channel for broadcasting system control information … Read more
Downlink Physical Channel of WCDMA Downlink Dedicated Physical Channel: Downlink DPCH Downlink Common Physical Channel: Common Control Physical Channel (CCPCH) Synchronization Channel ( SCH) Paging Indicator Channel (PICH) Acquisition Indicator Channel (AICH) Common Pilot Channel (CPICH) High-Speed Packet Downlink Shared Channel (HS-PDSCH) High-Speed Shared Control Channel (HS-SCCH) Uplink Physical Channel of WCDMA Uplink Dedicated Physical Channel: Uplink … Read more
BCCH(Broadcast Control Channels) Downlink Only. Broadcast information of the serving cell (System Information). Transmitted on timeslot zero of BCCH carrier. Read only by idle mobile at least once every 30 secs. SCH (Synchronization Channels) Downlink Only Carries information for frame synchronization. Contains frame number and BSIC (Base Station Identity Code). FCCH (Frequency Correction Channels) Downlink … Read more
Channel Bandwidth 5 MHz Duplex Mode FDD and TDD Downlink RF Channel Structure Direct Spread (DS) Chip Rate 3.84 Mcps Frame Length 10 ms Spreading Modulation Balanced QPSK (downlink) Dual-channel QPSK (uplink) Complex spreading circuit Coherent detection • User dedicated time multiplexed pilot (downlink and uplink) • common pilot in downlink Channel Multiplexing in Downlink … Read more
Support two basic modes: FDD and TDD modes High chip rate (3.84 Mcps) and data rates (up to 2 Mbps) Employs coherent detection on uplink and downlink based on the use of pilot symbols Inter-cell asynchronous operation Fast adaptive power control in the downlink based on SIR Provision of multirate services Packet data Seamless inter-frequency … Read more