UMTS: Alive and Well - 4G Americas
UMTS: Alive and Well - 4G Americas
UMTS: Alive and Well - 4G Americas
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parameterization was chosen in such a way that common sampling rates with GSM/EDGE <strong>and</strong> <strong>UMTS</strong>can be utilized to reduce complexity <strong>and</strong> cost <strong>and</strong> enable easy dual mode/multimode implementation.C.2.2.2.3SHARED CHANNEL STRUCTUREShared channel in the uplink is called Physical Uplink Shared Channel (PUSCH). The same set ofmodulations is supported as in PDSCH in downlink, but use of 64QAM is optional for devices up to Class5, in which it is m<strong>and</strong>atory. Also multi-antenna uplink transmission is not specified in the first phase ofLTE specifications. In the uplink direction up to 20 MHz b<strong>and</strong>width may also be used, with the actualtransmission b<strong>and</strong>width being multiples of 180 kHz resource blocks, identical to downlink resource blockb<strong>and</strong>width. The channel coding is the same as on the PDSCH. PUSCH may reach up to a 50 Mbps to 60Mbps user data rate with single antenna transmission using 16QAM modulation.C.2.2.2.4REFERENCE SIGNALTwo types of uplink reference signals are supported:1. demodulation reference signal, associated with transmission of uplink data <strong>and</strong>/or controlsignaling2. sounding reference signal, not associated with uplink data transmissionFor the generic frame structure, the demodulation reference signal is mapped to SC-FDMA symbol l = 3 .The same value ofk0as for the PUSCH transmitted in the long SC-FDMA symbols in the subframe shallbe used. The sounding reference signal is mapped to the last SC-FDMA symbol in a subframe in everysecond subcarrier.C.2.2.2.5CONTROL CHANNEL STRUCTUREPhysical Uplink Control Channel (PUCCH) carries uplink control information. The PUCCH is nevertransmitted simultaneously with the PUSCH. The block of bits to be transmitted on the physical uplinkcontrol channel are further coded with a UE-specific code sequence prior to modulation enabling multipleUEs’ PUCCHs to be code multiplexed on the same time-frequency resource.The PUCCH shall be mapped to a control channel resource in the uplink. A control channel resource isdefined by a code <strong>and</strong> two resource blocks, consecutive in time, with hopping at the slot boundary.Mapping of modulation symbols for the physical uplink control channel is illustrated in Figure C.26.www.3G<strong>Americas</strong>.org February 2010 Page 176
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