采用COTS器件的低轨星载收发信机设计与实现

Design and Implementation of a Low Earth Orbit Satellite-borne Transceiver Adopting COTS Devices

在性能、成本和可靠性的多重约束下,采用商用货架(Commercial Off-The-Shelf,COTS)器件设计了一种高性能、低成本星载收发信机。该收发信机的硬件设计不但可同时满足星地和星间应用需要,而且还具有支持多波束、多信道接入的特点。软件设计主要解决了大多普勒频偏条件下的低信噪比解调和变长以太网数据帧的高效处理等问题。地面测试结果表明,在250 kb/s^14 Mb/s信息速率范围内,误比特率低于1.0×10-6时所需的解调信噪比(E b/N 0)不超过2.8 dB,发射信号误差矢量幅度不超过1.9%,高速应用时处理时延可低至3.0 ms。为降低COTS收发信机的可靠性风险,分别在元器件、电路和系统层面进行了有针对性的可靠性保证措施。该设计经过了在轨测试的验证,对其他低轨商业通信载荷的研制有一定的参考价值。

Under the constraints of performance,cost and reliability,a high-performance and low-cost satellite-borne transceiver is designed by using commercial off-the-shelf(COTS)devices.The hardware design of the transceiver can not only meet the requirements of satellite-ground and inter-satellite applications,but also has the characteristic of supporting multi-beam and multi-channel access.The software design mainly solves the problems of low signal-to-noise ratio demodulation under the condition of large Doppler frequency shift,and efficient processing of variable-length Ethernet data frames.Ground test results demonstrate that within the information rate range of 250 kb/s^14 Mb/s,the required demodulation signal-to-noise ratio(E b/N 0),when the bit error rate is lower than 1.0×10-6,does not exceed 2.8 dB,the error vector amplitude(EVM)of the transmitted signal does not exceed 1.9%,and the processing delay is as low as 3 ms in high-speed applications.In order to reduce the reliability risk of the COTS transceiver,specific reliability assurance measures are carried out at device level,circuit level and system level respectively.The design has been verified by in-orbit test,and has certain reference value for the development of other low Earth orbit commercial communication payloads.