1、 Recommendation ITU-R M.2057-0(02/2014)Systems characteristics of automotive radars operating in the frequency band 76-81 GHz for intelligent transport systems applicationsM SeriesMobile, radiodetermination, amateurand related satellite servicesii Rec. ITU-R M.2057-0 Foreword The role of the Radioco
2、mmunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regula
3、tory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-
4、T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/IT
5、U-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (soun
6、d) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination betw
7、een fixed-satellite and fixed service systems SM Spectrum management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic
8、 Publication Geneva, 2014 ITU 2014 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R M.2057-0 1 RECOMMENDATION ITU-R M.2057-0 Systems characteristics of automotive radars operating in the frequency band 76-81 GH
9、z for intelligent transport systems applications (2014) Scope This Recommendation specifies the system characteristics of automotive radars operating under the radiolocation service in the frequency band 76-81 GHz. These technical and operational characteristics should be used in compatibility studi
10、es between automotive radars operating in the radiolocation service and systems operating in other services. The ITU Radiocommunication Assembly, considering a) that antenna, signal propagation, target detection, and large bandwidth characteristics for automotive radars are needed to optimally achie
11、ve their functions in certain frequency bands; b) that the technical characteristics of radars operating in the radiodetermination service are determined by the needs of the system and may vary widely from band to band; c) that representative technical and operational characteristics of systems oper
12、ating in frequency bands allocated to the radiodetermination service are necessary to determine the feasibility of introducing new types of systems; d) that procedures and methodologies are needed to analyse compatibility between radars operating in the radiodetermination service and systems operati
13、ng in other services, recommends that the systems characteristics for automotive radars operating in the frequency band 76-81 GHz for intelligent transport systems (ITS) applications as described in the Annex should be used for sharing/compatibility studies. 2 Rec. ITU-R M.2057-0 Annex Systems chara
14、cteristics of automotive radar systems operating in the frequency band 76-81 GHz for ITS applications 1 Introduction In the frequency band 76-81 GHz, radar systems in support of enhanced road safety are operated. Evolving demands related to automotive safety applications, including the reduction of
15、traffic fatalities and accidents require a range resolution for automotive radar systems leading to a necessary bandwidth of up to 4 GHz. 2 Technical characteristics of automotive radar systems operating in the frequency band 76-81 GHz Regarding functional and safety requirements, the automotive rad
16、ar systems operating in the 76-81GHz range can be separated in two categories: Category 1: Adaptive Cruise Control (ACC) and Collision Avoidance (CA) radar, for measurement ranges up to 250 metres the typical technical characteristics are listed in Table 1 as Radar A. For these applications, a maxim
17、um continuous bandwidth of 1 GHz is required. Such radars are considered to add additional comfort functions for the driver, giving support for more stress-free driving. Category 2: Sensors for high resolution applications such as Blind Spot Detection (BSD), Lane-Change Assist (LCA) and Rear-Traffic
18、-Crossing-Alert (RTCA), detection of pedestrians and bicycles in close proximity to a vehicle, for measurement ranges up to 100 metres the typical technical characteristics are listed in Table 1 as Radar B, Radar C and Radar D. For these high resolution applications, a necessary bandwidth of 4 GHz i
19、s required. Such radars directly add to the passive and active safety of a vehicle and are therefore an essential benefit towards improved traffic safety. The increased requirements for active and passive vehicle safety are already reflected in the requirements for vehicle testing. Radar E operates
20、with a higher field of view to enable high-resolution applications such as pedestrian detection, parking-aid, emergency braking at low speed ( 30 km/h). The technical parameters of radiolocation radar systems operating in the frequency bands 76-77 GHz and 77-81 GHz are presented in Table 1. Rec. ITU
21、-R M.2057-0 3 TABLE 1 Automotive radar characteristics in the frequency band 76-81 GHz Parameter Radar A(1)Automotive radar For front applications for e.g. for adaptive cruise control Radar B Automotive high-resolution radar For front applications Radar C Automotive high-resolution radar For corner
22、applications Radar D Automotive high-resolution radar Radar E Automotive high-resolution radar Very short range applications (e.g. parking-aid, collision avoidance at very low speed) Sub-band used (GHz) 76-77 77-81 77-81 77-81 77-81 Typical operating range (m) Up to 250 Up to 100 Up to 100 Up to 100
23、 Up to 50 Range resolution (cm) 75 7.5 7.5 7.5 7.5 Typical emission type FMCW, Fast-FMCW FMCW, Fast-FMCW FMCW, Fast-FMCW FMCW FMCW, Fast-FMCW Max necessary bandwidth (GHz) 1 4 4 4 4 Chirp bandwidth (GHz) 1 2-4 2-4 2-4 2 Typical sweep time (s) 10 000-40 000 for FMCW 10-40 for fast-FMCW10 000-40 000 f
24、or FMCW 10-40 for fast-FMCW 10 000-40 000 for FMCW 10-40 for fast-FMCW 2 000-20 000 for FMCW 10 000-40 000 for FMCW 10-40 for fast-FMCW Maximum e.i.r.p. (dBm) 55 33 33 45 33 Maximum transmit power to antenna (dBm) 10 10 10 10 10Max power density of unwanted emissions (dBm/MHz) 0 (73.5-76 GHz and 77-
25、79.5 GHz) 30 otherwise 30 30 13(2)30 Receiver IF bandwidth (3 dB) (MHz) 0.5-1 10 10 10 10 Receiver IF bandwidth (20 dB) (MHz) 0.5-20 15 15 15 154 Rec. ITU-R M.2057-0 TABLE 1 (end) Parameter Radar A(1)Automotive radar For front applications for e.g. for adaptive cruise control Radar B Automotive high
26、-resolution radar For front applications Radar C Automotive high-resolution radar For corner applications Radar D Automotive high-resolution radar Radar E Automotive high-resolution radar Very short range applications (e.g. parking-aid, collision avoidance at very low speed) Receiver sensitivity (dB
27、m)(3)115 120 120 120 120 Receiver noise figure (dB) 15 12 12 12 12 Equivalent noise bandwidth (kHz) 25 16 16 16 16 Antenna main beam gain (dBi) Typical 30, Maximum 45 TX: 23 RX: 16 TX: 23 RX: 13 TX: 35 max. RX: 35 max TX: 23 RX: 13 Antenna height (m) 0.3-1 above road 0.3-1 above road 0.3-1 above roa
28、d 0.3-1 above road 0.3-1 above road Antenna azimuth scan angle (degrees) TX/RX: 15 TX: 22.5 RX: 25 TX: 23 RX: 30 TX: 30 RX: 30 TX: 50 RX: 50 Antenna elevation HPBW (degrees) TX/RX: 3 TX/RX: 5.5 TX/RX: 5.5 TX/RX: 5.5 TX/RX: 5.5 (1)Radar type A is related to Recommendation ITU-R M.1452. (2) Maximum po
29、wer density of unwanted emission is specified at antenna input terminal. (3) The receiver sensitivity is determined using the equivalent noise bandwidth.Rec. ITU-R M.2057-0 5 3 Operational characteristics of automotive radar systems operating in the frequency bands 76-77 GHz and 77-81 GHz Automotive
30、 radar applications are evolving from providing additional comfort functions, such as Adaptive Cruise Control (ACC) and Collision Avoidance (CA) radar, to functions that significantly add to the passive and active vehicle safety. This requires systems that can detect objects in the close proximity (
31、in the order of 15 metres) of the vehicle, such as pedestrians or bicycles. Such applications require radar sensors that have a target separation capability of less than 10 centimetres. Radar sensors that provide this resolution require an operating bandwidth of 4 GHz. Radar A type sensors detect th
32、e relevant road traffic in order to adapt the speed of the vehicle to that of other vehicles ahead. To satisfy the demands for increased car safety, and depending on the application, one or more radar A type systems may be combined with additional radar B, C, D and E type sensors in one vehicle. Bas
33、ed on the sensor information, the data processing system in the vehicle will trigger the appropriate radar. Radar B, C, D and E type sensors cover the close proximity of a vehicle and will add additional active and passive safety functions, e.g. autonomous emergency braking, active blind spot assist
34、ance and lane change assistance. 4 Protection criteria The desensitizing effect on radars operated in this frequency band from other services of a CW, FMCW or noise-like type modulation is predictably related to its intensity. In any azimuth sectors in which such interference arrives, its power spec
35、tral density can simply be added to the power spectral density of the radar receiver thermal noise, to within a reasonable approximation. If the power spectral density of the radar-receiver noise in the absence of interference is denoted by N0and that of noise-like interference by I0, the resultant
36、effective noise power spectral density becomes simply I0+ N0. An increase of about 1 dB for the automotive radars would constitute significant degradation. Such an increase corresponds to an (I + N )/N ratio of 1.26, or a protection criterion I/N of about 6 dB. The aggregation factor can be very sub
37、stantial in the case of certain communication systems, in which a great number of stations can be deployed. The effect of pulsed interference is more difficult to quantify and is strongly dependent on receiver/processor design and mode of operation. In particular, the differential processing gains f
38、or valid-target return, which is synchronously pulsed, and interference pulses, which are usually asynchronous, often have important effects on the impact of given levels of pulsed interference. Several different forms of performance degradation can be inflicted by such desensitization. Assessing it will be an objective for analyses of interactions between specific radar types. _
