# Integrated Communication and Measurement System with BOC-Assisted OFDM
## 1 Introduction  
In recent years, unmanned aerial vehicles (UAVs) have become an important part of modern military development [1]. For UAVs, high-precision measurement and high-speed information transmission are necessary to realize flight and operational missions. Previously, communication and measurement functions have been designed independently to achieve high performance and reduce mutual interference. However, as the number and types of UAVs continue to increase, problems may arise between the various independent systems such as complex management, waste of resources, and difficulty in effective interaction. Therefore, the integration of communication and measurement is a general trend for future development [2; 3; 4; 5]. Many scholars in related fields have conducted numerous studies on integrated communication and measurement systems. Ref. [6] proposes the time and code division-orthogonal frequency division multiplexing (TC-OFDM) signal system for the integration of communication and measurement. By superimposing the ranging signal onto the orthogonal frequency division multiplexing (OFDM) signal, the TC-OFDM signal is simultaneously realized with signal acquisition and tracking. Ref. [7] proposes a method for simultaneous ranging and communication based on the physical layer (PHY) of multiband orthogonal frequency division multiplexing (MB-OFDM). The transmitter modulates one or multiple OFDM subcarriers with a low-frequency ranging signal, and the remaining subcarriers are adopted for communication. This approach requires a signal-to-noise ratio (SNR) greater than \(15\) dB to achieve a \(1\%\) range accuracy without interference. Ref. [8] proposes a two-step carrier phase estimation method for OFDM signal to improve the position accuracy. Although the proposed method can achieve sub-centimeter accuracy, it fails to realize communication. In addition, Ref. [9] proposes an integrated navigation and communication system based on OFDM in different scenarios. The authors combinethe block-type ranging pilot with the OFDM signal. The accuracy of the ranging error can reach 0.8 m. Refs. [10; 11] indicate that OFDM can possess combined communication and measurement capabilities and can provide an efficient spectrum utilization rate. Although many scholars have realized integration of communication and measurement based on OFDM modulation, the resulting systems have rarely met the high-precision measurement requirements. Refs. [12; 13] show that the modulation scheme has an important impact on the accuracy. The initial modulation scheme was a binary phase shift keying-rectangular (BPSK-R) modulation [14]. However, improving the accuracy requires endowing BPSK modulation with a wider bandwidth and better multipath performance [15]. To solve these problems, [PERSON] proposes a binary offset carrier (BOC) modulation [16; 17]. BOC modulation has significant benefits in terms of good spectral isolation from heritage signals, high-precision measurement, resistance to multipath interference, and flexible signal implementation [14]. Presently, BOC modulation is broadly adopted in modern global navigation satellite systems such as the Global Positioning System (GPS) [18], the European Galileo System [16], and the Beidou Navigation System (BDS) [19]. Ref. [20] proposes a multifunctional signal based on BOC and BPSK modulations. This methodology can achieve communication and measurement functions at the same frequency, and a 1% ranging accuracy is achieved when the carrier-to-noise ratio (CNR) is greater than 60 dB-Hz. Ref. [21] proposes a signal modulation method based on OFDM, combining the direct sequence spread spectrum and OFDM modulation technologies. High tracking accuracy is achieved by adopting high-frequency subcarriers to increase the energy of high-frequency signals. Many relevant works have combined OFDM or BOC modulation with other systems to achieve the integration of communication and measurement. However, researchers have rarely considered combining the OFDM system with the BOC system. Ref.