[BMSB.2018] Ranging and Positioning Algorithm Based on DTMB Syst...
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Ranging and Positioning Algorithm Based on
DTMB System
Xuan Wu
∗
, Chao Zhang
∗
and Saehyung Sohn
†
∗
Beijing National Research Center for Information Science and Technology
Department of Electronic Engineering, Tsinghua University, Beijing 100084, P.R. China
†
Smart Green City Lab, Sungkyunkwan University, Korea
x-wu17@mails.tsinghua.edu.cn, z
c@tsinghua.edu.cn, sohn6969@gmail.com
Abstract—Compared with Global Navigation Satellite System
(GNSS) which has been widely applied, the systems based on digi-
tal terrestrial television broadcasting (DTTB) for positioning need
to be further studied. In this paper, the localization algorithm
based on digital television terrestrial multimedia broadcasting
(DTMB) system is proposed. By utilizing the existing frame
structure of DTMB system, the distance measurement and
positioning methods are investigated in detail. The simulation
experiments prove that the proposed scheme can provide accurate
positioning results even under severe reception conditions.
Index Terms—DTMB, pseudo-range measurement, positioning
I. INTRODUCTION
Global Navigation Satellite System (GNSS) is now widely
applied in a variety of applications [1]. But, the satellite
positioning system has some shortcomings, such as very low
signal strength of received signal, the ionosphere clutter during
transmission and high Doppler effect caused by high-speed
satellite movement, etc. These unfavorable factors make GNSS
need to add auxiliary information in the navigation message
which increases the equipment costs.
The digital terrestrial television broadcasting (DTTB) sig-
nals are widely used in population settlements. Comparing
with GNSS, DTTB system has higher receiving power, lower
radio frequency (RF), and wider signal bandwidth [2]. In
Chinese digital television terrestrial multimedia broadcasting
(DTMB) system, the time-domain-synchronous orthogonal
frequency division multiplexing (TDS-OFDM) technology is
adopted, which has a natural advantage in resisting multi-
path. The signal frame, which consists of the frame header
and the frame body, is the basic unit of the transmission
signal in DTMB. Thanks to the optimized pseudo-noise (PN)
sequence in the frame header, better auto-correlation result
can be obtained. Furthermore, the frame structure is designed
to synchronize with the natural time by which the frame
transmission time can be known [3]. Therefore, using DTMB
signal to complete the positioning is feasible both in theory and
reality. It can be used as auxiliary and supplementary means
of GSNN.
Several literatures have studied the positioning issue using
DTTB signals. For the American advanced television systems
committee (ATSC) system, TxIDs were used to distinguish
transmit towers. Each tower is assigned a unique spread
spectrum signal to distinguish from the other transmit towers
and the pseudo-range is estimated by the correlation of TxID.
The positioning in the actual environment based on ATSC
is discussed in [4] and the improved method is introduced
in [5]. For the European digital video broadcasting-terrestrial
(DVB-T), the correlation of the frequency-domain pilots is
used to ranging [6] [7]. In DTMB system, both of the
frequency-domain pilots and TxIDs are not added to the signal
frame. Therefore, the above methods are not applicable if the
signal frame structure is not modified. A time-frequency joint
positioning scheme for TDS-OFDM systems is proposed in
[8]. However, the algorithm has poor performance in low SNR
condition. This paper proposes an algorithm that achieves good
positioning accuracy under low SNR.
The main contributions of this paper are summarized as
follows:
- Based on DTMB system, we propose a distance measure-
ment algorithm and a positioning algorithm without modifying
the existing frame structure of the transmitter.
- Simulation results show that the distance measurement and
positioning algorithms can achieve high estimation precision
even under severe transmission environments.
The rest of the paper is organized as follows. Section II
introduces the basic architecture of positioning system based
on DTMB. The positioning algorithm and ranging algorithm
are described in detail in Section III. Simulation results
in different situations are given in Section IV. Finally, we
conclude this paper in Section V.
II. P
OSITIONING SYSTEM ARCHITECTURE
DTMB system adopts TDS-OFDM technology with a PN
sequence serving as the guard interval (GI) of the OFDM
blocks and the training symbol. The DTMB system has three
kinds of frame structures as shown in Fig. 1. The length of
the PN sequence can be 420 symbols, 595 symbols or 945
symbols [9].
In the proposed ranging algorithm, we only need to use the
PN sequence carried by the frame header for synchronization
[10] [11], and do not have to demodulate the data carried by
the frame body. Therefore, the signal-to-noise ratio (SNR) re-
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2018 IEEE
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