# Advanced Technology in ATSC3.0: Boosting Data Signal Rates Using Polarization Properties and FSS +
## 1 Introduction  
In recent years, the Advanced Television Systems Committee 3.0 (ATSC 3.0) standard has been developed and adopted for terrestrial broadcasting to support higher-quality and more flexible services. ATSC 3.0 is gaining significant attention as a next-generation technology that enables the convergence of broadcasting and telecommunications. Compared to its predecessor, ATSC 1.0, it introduces numerous technical advancements, including ultra-high-definition (UHD) video delivery, support for mobile device reception, and enhanced error correction mechanisms [1, 2]. ATSC 3.0 is currently being deployed in North America, South Korea, and other regions around the world. The physical layer of ATSC 3.0 employs advanced transmission technologies such as bit-interleaved coded modulation (BICM), orthogonal frequency division multiplexing (OFDM), cell multiplexing, and layered division multiplexing (LDM) [3]. These technologies enable more efficient and flexible utilization of frequency resources compared to previous digital television broadcasting standards. Notably, the establishment of a single frequency network (SFN) is a key feature of ATSC 3.0, contributing to improved spectrum efficiency [4]. To support wide-area coverage in SFN configurations, ATSC 3.0 employs transmitter identification (TxID) techniques to distinguish signals from multiple transmitting stations [5, 6]. TxID sequences, which function as electronic watermarks, are embedded in each transmission and assign unique identifiers to each on-channel repeater (OCR). Historically, TxID schemes based on Kasami sequences have been widely used; however, their effectiveness is hindered by truncation errors and inter-code interference (ICI), leading to degraded identification accuracy [7]. To address these issues, alternative TxID sequences utilizing efficient matched filter (MF) architectures have been proposed [8]. However, these methods typically rely on extremely long spreading codes (e.g., 64,896 chips) to mitigate interference with broadcast signals, which significantly reduces the data transmission rate [9,10]. In this study, we propose a novel transmission scheme for ATSC 3.0 that leverages the polarization properties of electromagnetic waves to mitigate interference and enhance the data transmission rate. When a dipole antenna is used for signal transmission, the resulting electromagnetic waves exhibit a directional electric field--referred to as polarization--which affects the received power based on the antenna's orientation relative to the wave's polarization direction [11]. The maximum received power occurs when the antenna is aligned with the polarization, whereas misalignment leads to attenuation. Specifically, when using vertically and horizontally oriented antennas for transmission and reception, cross-polarization discrimination (XPD) results in a power attenuation of approximately 5-15 dB [12]. XPD, which reflects the variation in received power due to polarization orientation, is effective at reducing interference to broadcast signals. By exploiting XPD, it becomes possible to transmit additional data without significantly interfering with standard broadcast signals, even when using shorter spreading codes. This, in turn, improves the overall transmission rate. Moreover, a system based on XPD can be implemented without increasing the complexity of the existing ATSC 3.0 architecture [13,14]. Its integration requires only the addition of antennas with differing orientations, avoiding increased processing demands at both the transmitter and receiver. Additionally, frequency symbol spreading (FSS)--a technique that spreads OFDM symbols across the frequency domain--has gained attention for its ability to enhance the bit error rate (BER) performance in multipath fading environments [15]. In addition, frequency symbol spreading (FSS) is highly compatible with adaptive modulation techniques [16,17].