Single carrier
frequency division multiple access technique is a technique which deals with
the assignment of multiple users to a shared communication resource. It can be
linearly procoded OFDMA scheme i.e it has an additional DFT processing preceding the conventional
OFDMA processing. It has drawn great attention, as it is an attractive
alternative to OFDMA especially in the uplink communications where lower peak to
average power ratio (PAPR) greatly benefits the mobile terminal in efficiency
and it also reduces the cost of power amplifier.
The process
of transmission of SCFDMA is very similar to OFDMA. In this for each user the sequence of bits
that are transmitted are mapped in symbols like BPSK, QPSK or M-QOM.
This different
users are assigned with different fourier coefficients. This assignment is
carried out in mapping and demapping blocks. The receiver side includes one
demapping block, one IDFT block and one detection block for each user signal to
be received.
In this,
multiple access among users is made possible by assigning different users,
different sets of non overlapping sub carriers.
The distinguishing
feature of SCFDMA is that it leads to a single carrier transmit signal in
contrast with multicarrier transmission scheme in OFDMA.
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