Abstract—This paper investigates the cyclostationarity of China
multimedia mobile broadcasting (CMMB) signals. A scattered pilot
detection algorithm with lower complexity of CMMB signals based on
data smoothing for cognitive radio networks is proposed. First, the
received data in secondary user is smoothed by the first order lag filter.
Then the cyclic autocorrelation functions (CAFs) of the odd and even
orthogonal frequency division multiplexing (OFDM) symbols in
CMMB signals, as the decision statistics are calculated. According to
the signature of CMMB signals, appearing some peaks of scattered
pilots for the cycle frequency
0
α
=
around the delay lags
123
4
u
T
n ,n , ,
τ
= =
, as dominant peaks of CAF is used to detect the
CMMB primary user. We derive and simplify expressions of these two
decision statistics, and we use the OR rule to decide whether the
CMMB primary user is present or not. Simulation results show that by
using longer sensing time, the detection performance of the proposed
algorithm is significantly improved.
Keywords—
scattered pilot detection, cyclic autocorrelation
function (CAF), data smoothing, CMMB, cognitive radio networks.
I. INTRODUCTION
ADIO spectrum, an expensive and limited resource, is
surprisingly underutilized by licensed users. Such spectral
underutilization has motivated cognitive radio (CR)
technology, which enables secondary users (SUs) to
opportunistically access spectrum holes [1]. As a fundamental
and key issue in cognitive radio networks (CRNs), spectrum
sensing has been explored comprehensively [2]-[3]. There are
basically two spectrum sensing methods, narrowband sensing
and wideband sensing. In practice, due to either high
implementation complexity or high financial/energy costs,
This work was supported by the Foundation of Education Department of
Hubei Province, China (No. D20162603), the Foundation of Hubei University
of Arts and Science, China (No. 2016ZK020), National Natural Science
Foundation of China (Program No.61472136 and No.61772196, and Key
Project of Hunan Province of China Social Science Fund (Program
No.2016ZBB006), and Hunan Province of China Social Science Achievement
Evaluation Committee appraises and evaluates the subject of (Program
No.2016JD05).
Huiheng Liu is with the School of Physics and Electronic Engineering,
Hubei University of Arts and Science, Xiangyang 441053, Hubei, China
(corresponding author; e-mail: lhh117@163.com).
Zhengqiang Wang is with the School of Physics and Electronic Engineering,
Hubei University of Arts and Science, Xiangyang 441053, Hubei, China.
Weijin Jiang is with the School of Computer and Information Engineering,
Hunan University of Commerce, Changsha 410205, Hunan, China.
wideband sensing schemes are difficult to design [4]. Among
narrowband sensing techniques, such as the energy detection
(ED), matched filter detection (MFD) and cyclostationary
feature detection (CFD) are the most popular methods
addressed in the literature [5]-[6]. MFD needs perfect
knowledge of the primary user (PU) signal and channel
propagation which aren't known for SUs. ED doesn't need any
prior information on the PU signal. It is robust to unknown
fading channels. However, ED must know the background
noise, and it is very susceptible to the noise uncertainty. CFD
can well distinguish between the signal and noises, and it is
robust to the noise uncertainty. Though computational
complexity, CFD is frequently used for spectrum sensing,
especially for some signals with cyclostationary signature, i.e.
orthogonal frequency division multiplexing (OFDM). OFDM
is the most popular modulation scheme in communication and
broadcasting systems, such as digital video broadcasting -
terrestrial (DVB-T), worldwide interoperability for microwave
access (WiMax), long term evolution (LTE) and China
multimedia mobile broadcasting (CMMB) [7]. CMMB is a
mobile television and multimedia standard developed and
specified in China. It provides broadcasting and television
services for mobile phones, iPads, and other small screen
portable terminals using S-band satellites.
Most of the existing OFDM spectrum sensing methods make
use of the cyclic prefix (CP) or cyclostationarity of OFDM
signals [8]. Spectrum sensing for the signal with the
cyclostationarity is usually realized by calculating its cyclic
autocorrelation function (CAF). Its second-order cyclic
cumulants form with multiple cycle frequencies has been
addressed in [9]. Furthermore, in order to reduce the amount of
transmitted data, a censoring cooperative detection scheme also
was proposed in [9], which can achieve almost the same
detection performance when compared with the cooperative
scheme. The hard and soft decision combining cooperative
detection schemes of the CFD method were analyzed in [10].
Unfortunately, despite its high sensitivity, these detectors
suffered from high complexity. However, for some OFDM
signals embedded with pilot signals, i.e. CMMB, it is possible
to reduce the complexity of this method by calculating the CAF
with some special delay lags. We consequently propose a
scattered pilot detection algorithm based on data smoothing for
CMMB signals. According to the position of scattered pilots,
Scattered Pilot Detection of CMMB Signals
based on Data Smoothing in Cognitive Radio
Networks
Huiheng Liu, Zhengqiang Wang, Weijin Jiang
R
INTERNATIONAL JOURNAL OF CIRCUITS, SYSTEMS AND SIGNAL PROCESSING
Volume 12, 2018
ISSN: 1998-4464
204
资源评论
weixin_38520258
- 粉丝: 4
- 资源: 904
最新资源
- json的合法基色来自红包东i请各位
- 项目采用YOLO V4算法模型进行目标检测，使用Deep SORT目标跟踪算法 .zip
- 针对实时视频流和静态图像实现的对象检测和跟踪算法 .zip
- 部署 yolox 算法使用 deepstream.zip
- 基于webmagic、springboot和mybatis的MagicToe Java爬虫设计源码
- 通过实时流协议 (RTSP) 使用 Yolo、OpenCV 和 Python 进行深度学习的对象检测.zip
- 基于Python和HTML的tb商品列表查询分析设计源码
- 基于国民技术RT-THREAD的MULTInstrument多功能电子测量仪器设计源码
- 基于Java技术的网络报修平台后端设计源码
- 基于Python的美食杰中华菜系数据挖掘与分析设计源码
资源上传下载、课程学习等过程中有任何疑问或建议，欢迎提出宝贵意见哦~我们会及时处理！
点击此处反馈
