1、 Rep. ITU-R M.2110 1 REPORT ITU-R M.2110 Sharing studies between radiocommunication services and IMT systems operating in the 450-470 MHz band (2007) 1 Introduction and Scope Agenda item 1.4 of the 2007 World Radiocommunication Conference (WRC-07) calls upon the ITU-R “.to consider frequency-related
2、 matters for the future development of IMT-2000 and systems beyond IMT-2000 taking into account the results of ITU-R studies in accordance with Resolution 228 (Rev.WRC-03). Resolution 228 (Rev.WRC-03) resolves that the ITU-R should undertake among other studies, “.sharing and compatibility studies w
3、ith services already having allocations in potential spectrum for the future development of IMT-2000 and systems beyond IMT-2000 taking into account the needs of other services.” As part of its responsibility to provide the text to the CPM for Agenda item 1.4, Working Party 8F is studying several ca
4、ndidate bands for IMT systems including the 450-470 MHz band. ITU-R conducted sharing studies related to the candidate bands to determine the suitability of the candidate bands for IMT identification. This Report assesses the feasibility of sharing between IMT systems operating in the 450-470 MHz ba
5、nd and the radiocommunication services having a primary allocation in Section IV of Article 5 of the Radio Regulations Table of Frequency Allocations (henceforth referred to simply as the Table) in the 450-470 MHz band and in the adjacent 420-450 MHz and 470-480 MHz bands. This study addresses one m
6、ember of the IMT family, i.e. IMT-2000 CDMA Multi-Carrier (CDMA-MC). For ease of reference, CDMA-MC operating in the 450-470 MHz range is referred to as CDMA450 throughout the document. Further revisions of this Report may include other technologies in the IMT family. 2 Definitions and abbreviations
7、 2.1 Definitions No new definitions were introduced. 2.2 Abbreviations ACS Adjacent channel selectivity BS Base station BPSK Binary phase shift keying BW Bandwidth CDMA450 CDMA-MC system operating in the 450-470 MHz band CDMA-MC CDMA multi-carrier CPM Conference Preparatory Meeting dB Decibels DQPSK
8、 Differentially coherent quaternary phase shift keying DVB-H Digital video broadcast-handheld 2 Rep. ITU-R M.2110 DVB-T Digital video broadcast-terrestrial ERP Effective radiated power FDR Frequency dependent rejection ratio FM Frequency modulation FS Fixed system GMSK Gaussian minimum shift keying
9、IF Intermediate frequency kHz Kilohertz km Kilometers kW Kilowatt MCL Minimum coupling loss MS Mobile station MHz Megahertz MW Megawatts NMT Nordic mobile telephone OFR Off-frequency rejection OTR On-tune rejection PAMR Public access mobile radio PLRS Position location reporting system PMR Private m
10、obile radio P-MP Point-to-multipoint PSK Phase shift keying QAM Quadrature amplitude modulation QPSK Quadrature phase shift keying Rx Receiver TETRA Terrestrial trunked radio access WPR Wind profiler radar 3 Summary Sharing studies between one member of the IMT family, i.e. IMT-2000 CDMA multi-carri
11、er (CDMA-MC), operating in the 450-470 MHz band and the radiocommunication services having a primary allocation in Section IV of Article 5 of the Radio Regulations (RR) Table of Frequency allocations in the 450-470 MHz band and in the adjacent 420-450 MHz and 470-480 MHz bands were conducted. The st
12、udy evaluated the feasibility of sharing between CDMA450 system and radiolocation services, mobile, fixed, and/or broadcasting services in the above mentioned bands. The feasibility of certain scenarios is subject to a trade off between technical, regulatory and economical factors. In this Report di
13、fferent points of view have been reflected which correspond to different trade off choices. The views are by no means excluding other points of views. The conclusions below reflect only the studies made in this Report. The results of the study are summarized in the following tables corresponding to
14、each scenario evaluated. Rep. ITU-R M.2110 3 CDMA450 system interfering with radiolocation systems: TABLE 1 Results of the study of CDMA450 system interfering with radiolocation systems CDMA450 base station CDMA450 mobile station Radiolocation system Separation distance Separation distance/filtering
15、 Separation distance Separation distance/filtering Ground-based radars (5 MHz Rx. BW) 17.45 km 1 km/50 dB 8.29 1 km/40 dB Shipborne surveillance radars (2 MHz Rx. BW) 8 km 1 km/30 dB 4 1 km/20 dB Airborne surveillance radars (1 MHz Rx. BW) 12 km 1 km/20 dB 31.94 1 km/30 dB PLRS radars (3 MHz Rx. BW)
16、 2 km 1 km/10 dB 16 MHz Less stringent of 42 dBc/30 kHz or 54 dBm/1.23 MHz at 885 kHz to 1.98 MHz Less stringent of 54 dBc/ 30 kHz or 54 dBm/ 1.23 MHz at 1.98 MHz to 4 MHz 36 dBm/100 kHz at 4 MHz CDMA450 carrier allocation(4)First carrier (MHz) Second carrier (MHz) Third carrier allocation (MHz) Bas
17、e station receive 453.35 454.6 454.6 455.85 455.85 457.1 Mobile station receive 463.35 464.6 464.6 465.85 465.85 467.1 (1)These values correspond to the CDMA-MC technology operating in the 450-470 MHz band and are derived from the TIA 97/98-E specifications. (2)ACS values are derived from the receiv
18、er sensitivity, target Eb/No specifications, and the single-tone desensitization test specified in the TIA 97/98-E specifications. (3)The transmitter spurious emission values correspond to the CDMA-MC technology operating in the 450-470 MHz band and are derived from the TIA 97/98-E specifications. (
19、4)The typical carrier allocation of the CDMA-MC technology operating in the 450-470 MHz band is derived from the band Class 5 (sub-band A) specification of the TIA 97/98-E specifications. Rep. ITU-R M.2110 9 4.2 Protection criteria The protection criterion for CDMA450 systems used in this study was
20、taken to be an I/N value of 6 dB, consistent with that specified in Report ITU-R M.2039. 5 Sharing studies between CDMA450 and systems in the radiolocation service 5.1 Allocation in the Table of Frequency allocations The radiolocation service is allocated on a primary basis in all three ITU Regions
21、in the 430-440 MHz band. The 420-430 MHz and 440-450 MHz bands are allocated to the radiolocation service on a secondary basis except in Australia, the United States of America, India, Japan and the United Kingdom where they are primary as a result of footnote RR 5.269, and in Canada as a result of
22、footnote RR 5.285. Thus an adjacent band study between radiolocation systems and CDMA450 systems was performed to assess the amount of separation distances and/or guard bands needed to enable them to co-exist with each other. The following four cases were evaluated in the sharing study: a) CDMA450 b
23、ase station to radar receivers b) CDMA450 mobile station to radar receivers c) Radar transmitter to CDMA450 base station d) Radar transmitter to CDMA450 mobile station. 5.2 Technical characteristics of radiolocation systems In the 420-450 MHz frequency range, administrations have developed and deplo
24、yed a variety of mobile and transportable radar systems that operate on land, on ships, and in aircraft. 5.2.1 Ground-based space object tracking radars Ground radars are used for space object tracking and cataloguing by using very high power (up to 5 MW) transmitter powers and high antenna gains. T
25、he radars operate continuously; around the clock and year round. They scan from surveillance “fence” from around 3 up to 60 in elevation, in 120 sectors in azimuth. The radar receivers are very sensitive in order to detect returns from exo-atmospheric and space objects. Because of their specialized
26、function and requisite design characteristics (e.g. very large antenna arrays) these particular ground radars are not numerous, but because of their sensitivity and function they deserve special recognition and protection. Recommendation ITU-R M.1462, contains the nominal technical characteristics o
27、f these radars. Table 8 lists the RF parameters of these radars that were used in the sharing study. 5.2.2 Shipborne surveillance radars Shipborne surveillance radars are also operated in the frequency range 420-450 MHz. They normally operate at sea, though operations in coastal waters as well in na
28、val ports should be expected. As is typical with surveillance radars, the system scans 360 in azimuth, and operations are on a continuous basis. Table 8 lists the RF parameters of these radars that are used in the sharing study and derived from Recommendation ITU-R M.1462. 5.2.3 Airborne surveillanc
29、e radars The 420-450 MHz band is an essential band for the operation of airborne radars. These systems operate worldwide, for extended periods (hours to days) in their intended areas of operation. Long-range object detection, acquisition, and tracking are essential functions to sense and control air
30、 10 Rep. ITU-R M.2110 traffic. Ground-based radars are extremely limited by the radar horizon, and the employment of long-range radars on airborne platforms is an excellent way to extend individual radars capability. Similar to ground air surveillance radars, airborne radars employ rotating scans in
31、 azimuth and scan over a specified range in elevation either by electronically scanning in elevation or by using a relatively wide elevation beam-width. The radar operates during aircraft ascent and descent as well as at operating altitudes; aircraft ceiling altitude is around 12 000 m. Table 8 list
32、s the RF parameters of these radars that were used in the sharing study and derived from Recommendation ITU-R M.1462. 5.2.4 Position location reporting system (PLRS) Another type of service that operates in the 420-450 MHz range is the PLRS. The nominal technical characteristics of the PLRS were der
33、ived from Doc. 7C/239 (22 September 2002) Compatibility of spaceborne synthetic aperture radars (SAR) with services allocated for operation in the 430-440 MHz band”1. TABLE 8 Technical characteristics of the radiolocation systems Value Parameter Ground-based space object tracking radars Shipborne su
34、rveillance radars Airborne surveillance radars PLRS Tuning range 420-450 MHz 420-450 MHz 420-450 MHz 425.75-446.75 MHz Peak RF output power 1-5 MW 2 MW 2 MW 0.4, 3, 20, 125 W Pulse duration (if simulation is needed, this may be useful) 0.25, 0.5, 1.2, 4, 8, 16 ms 0.5 s 1, 2, 4, 8 s 824.6 s Duty cycl
35、e (average) 25% Not available Not available Not available Pulse modulation Search: 100-350 kHz linear FM chirp; Track: 1 or 5 MHz linear FM chirp Unmodulated pulses Unmodulated pulses Continuous phase modulation Pulse repetition rate Up to 41 Hz Not available 0.1 to 2 kHz 32 Hz (master station); 20
36、Hz (user unit) Antenna type Planar array (22 m diameter) Parabolic reflector Yagi element array or planar array 4 element stacked dipole (master station); stacked dipole (Gnd user unit); blade (air user unit) 1Although, Doc. 7C/239 calls PLRS a radar system, it is a radiodetermination system. PLRS w
37、as considered in the study because of the ITU-R texts that refer to them as radar systems. Table 8 below lists the RF parameters of these radars that were used in the sharing study. Rep. ITU-R M.2110 11 TABLE 8 (end) Value Parameter Ground-based space object tracking radars Shipborne surveillance ra
38、dars Airborne surveillance radars PLRS Antenna gain 38.5 dBi 30 dBi (mainlobe); 0 dBi (median sidelobe) 22 dBi 6 dBi (master station); 4 dBi (Gnd user unit); 0 dBi (air user unit) Antenna scan 3-85 elevation; 60 azimuth per each of 2 planar arrays for a total of 240 azimuth scan 360 azimuth 60 el (m
39、echanically positioned or elec-tronically scanned); 360 azimuth at 3-7 rpm Not applicable Antenna beamwidth 2.2 elevation; 2.2 azimuth Not available 6-20 elevation (depending upon scan type); 6 azimuth 43, 40, 20, 90 elevation (manpack, vehicle, master station, plane) 360 azimuth Antenna height(1)10
40、 m 20 m 5 000 m 10 m Polarization Circular Circular(2) Horizontal Vertical Receiver noise level 142 dBW(3) 136 dBW 139 dBW(4)133 dBW Receiver bandwidth 1 or 5 MHz (depending on chirp width) 2 MHz 1 MHz 3 MHz Receiver Protection Threshold I/N 60 Receiver IF image frequency rejection (dB) 50 Receiver
41、IF bandwidth (kHz) 350 (low-mode), 120 (hi-mode) Receiver noise floor(4)141 dBm/ 350 kHz Rise time. tr0.1 s Protection criteria I/N (dB) 10 (1)Users of this table should exercise caution in using combinations of these values to represent a “typical” or “worst case” profiler. For example, a profiler
42、operating with a peak power of 50 kW while using pulses to yield a height resolution of 150 m would be an unusual system. (2)Derived from NTIA Report 93-301, NOAA Special Report. (3)The maximum operating height depends upon the product: (average power) (antenna effective area). (4)NTIA Report 93-301
43、 states that the noise floor of wind profiler radars at 404 MHz is 14 1 dBm/350 kHz. It is assumed that wind profiler radars at 449 MHz will also have the same noise floor. 5.3 Protection criteria Recommendation ITU-R M.1462 provides the protection criteria to be used for the interference assessment
44、 of radars. The Recommendation notes that generally a signal from another service resulting in an I/N ratio below 6 dB is permissible by the radar users for signals from the other service having a continuous-wave or noise-like type modulation. An I/N ratio of 6 dB results in a (I + N)/N of 1.26 or a
45、pproximately 1 dB increase in the radar receiver noise power. This Report used an I/N of 6 dB as the protection criteria for all radars studied except for the wind profiler radars where a more stringent protection criterion of 10 dB, which correlates to less than 0.5 dB of noise floor increase, was
46、used. 5.4 Methodology An adjacent band study between the radiolocation systems and CDMA-MC operating between 450-470 MHz band was performed to assess the separation distance and/or the size of guard bands needed between the two systems to operate without exceeding the protection criterion of each sy
47、stem. Recommendation ITU-R M.1461 identifies two types of interference mechanisms where Rep. ITU-R M.2110 13 radiolocation systems can degrade the performance of other systems. These mechanisms include the front-end overload (or blocking) and the radar emissions coupled through the receiver RF/base
48、band/IF pass band. For the case of radars interfering with the CDMA450 systems, both mechanisms were assessed to determine the amount of separation and/or guard bands needed between the two systems. Equations and sample calculations corresponding to each case are added in the relevant sections of th
49、e analyses. For the case of CDMA450 interfering with the radars the frequency dependent rejection (FDR) analysis was used. FDR is the amount of attenuation offered by an electronic receiver to a transmitted signal. This attenuation is composed of two parts: on-tune rejection (OTR) and off-frequency rejection (OFR). FDR (f) = OFR (f) + OTR (1) where: FDR: rejection provided by a receiver to a transmitted signal as a result of both the limited bandwidth of the receiver with respect to the emissi
