In order to protect any and all MLS equipped aircraft within the frequency protected service volume, whenever there is a required separation distance between a transmitter (in this case the RNSS Earth station), the distance separation is referenced to the fixed ground transmitter, which is the center of a circle whose radius is the coverage range, i.e., 41.7 km. 6 Issues for future work The following issues are identified for future work: For RFI to RNSS feeder link receivers and service downlink receivers (Cases 1, 2 and 3): The MLS may need to be allotted more of the RNSS interference budget than proposed − in this analysis. The interference apportionment values require further study. It is unclear how the OCI high gain antenna is used to transmit DPSK data over a 360o − azimuth coverage. Further information/study is needed before incorporating OCI antenna information in this Report. Updates to the analysis. – Study potential benefits of improved RNSS receiver filtering. − Aggregate effect of additional non- RFI to FL downlink and service link receivers. – For RNSS transmitters interfering with receivers (previously Cases 4, 5 and 6): Verify whether a feeder link earth station can be located under an approach frequency – protected coverage volume. General issues: Analysis based on Galileo information (input to April meeting 4C/218). – 7 Conclusions TBD. Annex A Interference density calculations including RF/IF filtering effect A.1 RNSS service downlink receiver A 15th order Butterworth filter in Figure A-1 is used to approximate the RNSS service downlink RF/IF filter, with a 10 MHz cutoff frequency and a minimum of dB/MHz receiver’s –10 out-of-band roll-off. A-1 Simulated RNSS service downlink receiver’s RF/IF filter Figure A-2 shows the RNSS service downlink PSD, the unfiltered MLS DPSK PSD, and the filtered (RNSS receiver RF/IF filter with dB/MHz OOB roll-off) MLS DPSK PSD. –10
In order to protect any and all MLS equipped aircraft within the frequency protected service volume, whenever there is a required separation distance between a transmitter (in this case the RNSS Earth station), the distance separation is referenced to the fixed ground transmitter, which is the center of a circle whose radius is the coverage range, i.e., 41.7 km. 6 Issues for future work The following issues are identified for future work: For RFI to RNSS feeder link receivers and service downlink receivers (Cases 1, 2 and 3): − The MLS may need to be allotted more of the RNSS interference budget than proposed in this analysis. The interference apportionment values require further study. − It is unclear how the OCI high gain antenna is used to transmit DPSK data over a 360o azimuth coverage. Further information/study is needed before incorporating OCI antenna information in this Report. – Updates to the analysis. − Study potential benefits of improved RNSS receiver filtering. – Aggregate effect of additional non- RFI to FL downlink and service link receivers. For RNSS transmitters interfering with receivers (previously Cases 4, 5 and 6): – Verify whether a feeder link earth station can be located under an approach frequency protected coverage volume. General issues: – Analysis based on Galileo information (input to April meeting 4C/218). 7 Conclusions TBD. Annex A Interference density calculations including RF/IF filtering effect A.1 RNSS service downlink receiver A 15th order Butterworth filter in Figure A-1 is used to approximate the RNSS service downlink receiver’s RF/IF filter, with a 10 MHz cutoff frequency and a minimum of –10 dB/MHz out-of-band roll-off. A-1 Simulated RNSS service downlink receiver’s RF/IF filter Figure A-2 shows the RNSS service downlink PSD, the unfiltered MLS DPSK PSD, and the filtered (RNSS receiver RF/IF filter with –10 dB/MHz OOB roll-off) MLS DPSK PSD.
ACP-WGF22-IP19-MLS%20vs%20RNSS.docx