The Starlink system has eight Ku-band downlink channels, each with 250 MHz bandwidth, covering 10.7–12.7 GHz. It also has eight Ku-band uplink channels, each with 62.5 MHz bandwidth, covering 14.0–14.5 GHz. These channels may be dynamically assigned among different satellites, among different beams on the same satellite, and even among multiple terminals within the same beam. How exactly are these…
The Starlink terminal provides a gRPC service, which makes it possible to access information that is not displayed in the Starlink app. For example, the hardware version reported by my Starlink Mini through gRPC is: “hardware_version”: “mini1_panda_prod2” mini1: identifier for the first-generation/first-version Starlink Mini hardware platform panda: an internal Starlink hardware/platform codename.…
After reading the core Starlink patent US12003350, my strongest impression is this: From a communications perspective, Starlink largely adopts technology comparable to LTE from about 18 years ago. Starlink can be viewed as a simplified SISO LTE system or a SISO Wi-Fi 6 system, with carrier aggregation,. Although it incorporates onboard processing, digital beamforming, and phased-array antennas,…
I continued reading the Starlink patent US12003350 and summarized several system-level details. The patent was filed in early 2021, so readers should consider its timeliness accordingly. Multiple Access Starlink uses a combination of OFDMA and TDMA for multiple access. Duplex Mode Although all Starlink links operate in Frequency Division Duplex (FDD), with separate uplink and downlink frequencies,…
I continued reading the Starlink patent US12003350. Some aspects of the satellite capacity calculation remain ambiguous, and I welcome further discussion. The patent was filed in early 2021, so readers should consider its timeliness accordingly. The patent defines links and RF links as follows. FIG.4 defines a link from the perspective of the user terminal (UT). A link is an L3 connection to a UT,…
I continued reading the Starlink patent US12003350 and summarized several system parameters. The patent was filed in early 2021, so readers should consider its timeliness accordingly. According to FIG.21, Starlink uses two types of modem chips/modules based on capability of demodulation bandwidth and data rate. Modem for the Ku-band User Link This modem is used for: Terminal reception of a 250 MHz…
I continued reading the Starlink patent US12003350 and summarized the information related to the use of the Unique Word (UW). The patent was filed in early 2021, so readers should consider its timeliness accordingly. The UW is used differently on different communication links. Satellite–Terminal Link Uplink: When multiple terminals access the same satellite, each terminal is assigned a different…
I continued reading the Starlink patent US12003350 and summarized the information related to modulation and channel coding. The patent was filed in early 2021, so readers should consider its timeliness accordingly. Starlink supports the following modulation schemes: BPSK QPSK 8-QAM 16-QAM 32-QAM 64-QAM Unlike Wi-Fi and LTE, Starlink includes 8-QAM and 32-QAM. A possible reason is that satellite…
I continued reading the Starlink patent US12003350 and came across the following statement: A small change in clock rate is also caused by special (motion) and general (gravity) relativistic effects but it is quite small in low Earth orbits (about 0.2 ppb or parts per billion). This is the relativistic effect considered by Starlink when analyzing synchronization error sources in an OFDM system.…
Analysis of measured Starlink uplink signals and the Starlink patent US12003350 shows that the pilot structure is specifically designed for LEO satellite broadband access. Compared with terrestrial cellular systems and Wi-Fi, the similarities and differences are as follows. The most distinctive feature of the Starlink pilot design is the pilot structure embedded within data OFDM symbols. It uses…