Proposal for the spectrum mask in IEEE

Transcription

1 Proposal for the spectrum mask in IEEE IEEE Presentation Submission Template (Rev. 8) Document Number: IEEE c-01/27 Date Submitted: Source: Lars Lindh Nokia Research Center P.O. Box 407, FIN NOKIA GROUP, Finland Jay Klein Ensemble Communications, Inc 6256 Greenwich Dr,. Ste 400 San Diego, CA USA Venue: IEEE Session #13, Orlando, May 14-18, 2001 Purpose: This document is a contribution about spectrum mask requirements in Notice: This document has been prepared to assist IEEE It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor grants a free, irrevocable license to the IEEE to incorporate text contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE IEEE Patent Policy: The contributor is familiar with the IEEE Patent Policy and Procedures (Version 1.0) < including the statement IEEE standards may include the known use of patent(s), including patent applications, if there is technical justification in the opinion of the standards-developing committee and provided the IEEE receives assurance from the patent holder that it will license applicants under reasonable terms and conditions for the purpose of implementing the standard. Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair <mailto:r.b.marks@ieee.org> as early as possible, in written or electronic form, of any patents (granted or under application) that may cover technology that is under consideration by or has been approved by IEEE The Chair will disclose this notification via the IEEE web site

2 IEEE PHY Proposal for the spectrum mask

3 History of the spectrum masks in /D1 Subscriber station transmitter: Per relevant local regulation requirements Basestation transmitter: TBD by co-existence group /D2 Subscriber station transmitter: Per relevant local regulation requirements Basestation transmitter: Per relevant local regulation requirements Session #12 Subscriber station transmitter: Apply block spectrum mask from co-existence document Basestation transmitter: Apply block spectrum mask from co-existence document

4 Interpreting the block spectrum mask Proposed in Session #12 As no written contribution clarifyng the corner points of the spectrum mask was given the following interpretation is assumed: According to the co-existence document the unwanted emission spectral density should be attenuated by at least A=11+40*f offset /B 0 db where f offset is the frequency offset from the band edge and B 0 is the occupied bandwidth. Attenuation greater than 50 db is not required. The occupied bandwidth is defined as the bandwidth containing 99% of the total mean emitted power.

5 Computing the occupied bandwidth The occupied bandwidth can be computed as a function of the nominal bandwidth by solving the following equation: x B H ( f ) 2 df = 0.99 B H ( f ) 2 df 0 0 where H(f) is the transfer function of the square-root raised cosine pulse defined for baseband pulse shaping in and B is the nominal bandwidth Solving the equation will give x=0.882 which implies that the occupied bandwidth is given by B 0 = 0.882B The spectrum mask expressed as a function of the nominal bandwidth is then given by A~11+45*f offset /B (db)

6 Spectral mask proposed in Session #12 db With this information we can finally draw the spectrum mask proposed in session # B/2 3B/2

7 Net Filter Discrimination (NFD) S(f) Receiver filter H(f) Adjacent channel Spectrum S I (f) Interference Ratio between the power transmitted by the interfering system and the portion that can be measured after the receiver filter in the adjacent channel NFD = + S I + S I ( f ) df ( f ) H ( f ) 2 df f

8 ETSI spectrum masks ETSI has defined the System A, System B and System C spectrum masks in EN The ETSI spectrum masks and the Session #12 spectrum masks can be compared by computing the NFD for each of them assuming an ideal root-raised cosine receiver filter with roll-off 0.25 TypeUnitOrDepartmentHere TypeYourNameHere NFD (db) System A 24.6 System B 26.7 System C 30.9 Session #1225.4

9 ETSI A, B and C masks and Session #12 mask db ETSI System A ETSI System B ETSI System C Session # B/2 3B/2

10 Observations has a good chance of becoming an international standard. In Europe equipment in the GHz range must conform to the relevant ETSI System masks. It is noted that the Session #12 spectrum mask does not meet the requirements of any of the ETSI system masks. ETSI System masks are an example of a requirement of the "local regulator". When using ETSI masks the most stringent mask associated with the modulation complexity in the adjacent channels should be used. ETSI System masks tends to be more "anatomic" than the Session #12 spectrum mask meaning that they are modeled to better accommodate typical PA:s and still having a good NFD value. The Session #12 spectrum mask is also very stringent in the upper part of the adjacent channel making it hard to deal with fifth order intermodulation products. Where local requirements are more relaxed a spectrum mask according to session #12 might be used

11 Conclusions The conclusion is to revert to the decision in /D2: Subscriber station transmitter: Per relevant local regulation requirements Basestation transmitter: Per relevant local regulation requirements