Abstract—The decoding of Downlink Control Information
(DCI) in LTE is based upon a process that is defined as a blind
decoding which depends on a number of decoding attempts on
a number of Physical Downlink Control Channel (PDCCH)
candidate locations for a number of defined DCI formats. In
this paper, two proposed designs for DCI decoder are
presented. The first decodes based upon monitoring PDCCH
candidate locations serially. This design can perform the whole
44 decoding attempts within 87.3 % of the whole OFDM
symbol time with extended cyclic prefix. So, it's well suited for
Multicast/Broadcast over Single Frequency Network (MBSFN)
subframes. However, this design doesn't meet the worst-case
time of an LTE OFDM symbol with normal cyclic prefix.
Therefore, a second design is proposed that exploits parallelism
to enable fast blind decoding process. The proposed parallel
design proves efficiency in meeting decoding time constraints
besides, consuming a little power with a proven efficiency in
utilization area perspective. The proposed parallel design
performs all of 44 decoding attempts in a time of 7.8 μs which
is only 11.7 % of an LTE useful OFDM symbol time with a
logic power consumption of only 17000 μW. The proposed
designs are simulated using Modelsim 6.4a and implemented in
Plan Ahead 14.4 in 28 nm technology, Virtex7 FPGA kit of
part number XC7V2000T, which is characterized by high
performance and large capacity.
Index Terms—LTE, UESSS, CSS, DCI, PDCCH, UE.
Mohamed S. Abo Zeid, Mohamed E. Nasr, and Salah El Deen A.
Khamis are with Electronics and Electrical Communications Dept., Faculty
of Engineering, Tanta University, Tanta and 31527, Egypt (e-mail:
m1_saeed@yahoo.com, salah.khamis@f-eng.tanta.edu.eg, mnasr@feng.
tanta.edu.eg).
Khaled M. Elsayed is with Electronics and Electrical Communications
Dept., Faculty of Engineering, Cairo University, Giza and 12613, Egypt (email:
author@lamar. colostate.edu).
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Cite:Mohamed S. Abo Zeid, Khaled M. Elsayed, Mohamed E. Nasr, and Salah El Deen A. Khamis, "Efficient Design and Implementation of LTE Downlink Control Information Decoder," International Journal of Computer Theory and Engineering vol. 6, no. 2, pp. 160-169, 2014.
