doc.: IEEE g Submission March 2009 Michael SchmidtSlide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Multi-Rate PHY Proposal for the TG4g PHY Amendment Date Submitted: March 2009 Source: Michael Schmidt, Dietmar Eggert, Frank Poegel, Torsten Bacher, Sascha Beyer, Atmel Contact: Michael Schmidt, Atmel Voice: , Re: TG4g Call for proposals Abstract: PHY enhancements towards TG4g supporting multiple data rates Purpose: PHY proposal for the TG4g PHY amendment Notice:This document has been prepared to assist the IEEE P 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 acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P doc.: IEEE g Submission March 2009 Michael SchmidtSlide 2 Overview Flexible but simple binary block coding GMSK modulation Chip Rate SHR/PHR structure Frequency Hopping Extension of the European Frequency Band doc.: IEEE g Submission March 2009 Michael SchmidtSlide 3 Coding and Modulation doc.: IEEE g Submission March 2009 Michael SchmidtSlide 4 Binary Block Coding Simple C(K=4,N) binary block coding Binary coefficients (chips) Considerably simplifies TX and RX architecture Small number of code words (2 K = 16) Allows simple ML-soft decision decoding Flexible code length N to adjust the data rate doc.: IEEE g Submission March 2009 Michael SchmidtSlide 5 Binary Block Coding Adjust data rate by code length N out of {4,8,16,32,64,128} High Data Rate: N = 4,8 short range Medium Data Rate: N = 16,32 (like DSSS for IEEE O-QPSK PHYs) medium range Low Data Rate: N = 64,128 long range, higher multipath robustness Improved SHR and PHR detection doc.: IEEE g Submission March 2009 Michael SchmidtSlide 6 Binary Block Coding Within PSDU, more advanced but more complex coding conceivable, since large PSDU lengths are desired C(k,N) block coding with K > 4 obtaining a relevant coding gain Low rate coding within SHR and PHR doc.: IEEE g Submission March 2009 Michael SchmidtSlide 7 Binary GMSK Modulation Improved spectral efficiency versus O-QPSK Constant envelope modulation Reasonable performance Simple differential demodulation for BT approx. 0.5 (no Trellis- based detection required) GMSK is detectable for IEEE legacy devices using O-QPSK with appropriate spreading doc.: IEEE g Submission March 2009 Michael SchmidtSlide 8 Chip Rate 2 MHz IEEE 2.4 GHz ISM No need for frequency hopping for 1 W TX power (FCC CFR 47) 1 MHz IEEE MHz No need for frequency hopping for 1 W TX power (FCC CFR 47) < 0.5 MHz Need for frequency hopping for 1 W TX power (FCC CFR 47) >= 75 hopping 2.4 GHz ISM >= 50 hopping MHz doc.: IEEE g Submission March 2009 Michael SchmidtSlide 9 SHR + PHR Problem with IEEE O-QPSK PHYs: Relative short duration of SHR and PHR, hard for: antenna diversity, channel estimation PHR is not sufficiently protected More preamble bytes or low rate transmission, e.g. C(4,128)- coding doc.: IEEE g Submission March 2009 Michael SchmidtSlide 10 Frequency Hopping (FH) Increased robustness against interferer GMSK modulation applied in the 2.4 GHz ISM band allows tighter channel spacing than 5 MHz However, FH addresses many issues to be solved: FH Synchronisation (e.g. FHS packet information) Clock frequency accuracy Hopping sequences Power efficiency doc.: IEEE g Submission March 2009 Michael SchmidtSlide 11 Extension of European Frequency Band Harmonized standard EN defines frequency band of 863 MHz 870 MHz with different power limits for digital modulation systems using DSSS Duty cycle limitations do not apply to systems using Listen Before Talk techniques combined with Adaptive Frequency Agility (AFA) doc.: IEEE g Submission March 2009 Michael SchmidtSlide 12 DSSS Proposal for MHz channels with RF bandwidth of 0.6 MHz 863.5 MHz, MHz, MHz with reduced power of -4.5 dBm/100 kHz 865.3 MHz, MHz, MHz, MHz with increased output power of 6.2 dBm/100 kHz 868.3 MHz IEEE legacy channel 868.9MHz and MHz using -0.8 dBm/100 kHz output power channels with RF bandwidth up to 1.4 MHz 864.1 MHz with reduced power of -4.5 dBm/100 kHz 865.8 MHz and MHz with increased output power of 6.2 dBm/100 kHz 868.3 MHz IEEE legacy channel 869.3MHz using -0.8 dBm/100 kHz output power doc.: IEEE g Submission March 2009 Michael SchmidtSlide 13 FHSS with 863 870 MHz Listen Before Talk (LBT) has to be applied at each hopping channel. Carrier power is limited to 25 mW erp