DSSS proposal update Doc: IEEE g 07/09/2014 Slide 1 Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ Discussion on United DSSS MR-OQPSK Solution on 780 and 915Mhz] Date Submitted: [ Jan 2010 ] Source: [Xiang Wang, Liang Li, Yaoxian Fu, Jie Shen,] Company: [SIMIT/WSNIRI/Vinno/Huawei] [ Re: [ TG4g ] Abstract: Purpose:Suggestions for Harmonization of the DSSS PHY 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

DSSS proposal update Doc: IEEE g Fully support the United MR-QPSK solution for 780MHz and 915MHz for IEEE g It’s more reasonable while there are the similar frequency bands and the same chip rate. It’s a good idea to convey a frequency ranging from 780MHz to 915MHz from a PLL design point of view The same parameters are lead to same baseband processor and transceiver structure It also provides the back compatible to solutions in , 15.4C United Solutions on 915 and 780 Mhz bands

DSSS proposal update Doc: IEEE g Analysis the performances for united MR-OQPSK on both bands Find the better united solutions Discussion

DSSS proposal update Doc: IEEE g Solution 1 Chip Rate (kchips/s) RateModeDifferential Encoding Spreading½ rate FEC + Interleav- ing Data Rate (kbps) 10000No(32,4) DSSS Yes62.5 1No(16,4) DSSS Yes125 2No( 8,4) DSSS Yes250 3NoNoneYes500 SHR and PHR Spreading (32,1) DSSS

DSSS proposal update Doc: IEEE g Solution 2 Chip Rate (kchips/s) RateModeDifferential Encoding Spreading½ rate FEC + Interleav- ing Data Rate (kbps) 10000Yes(16,1) DSSS Yes No(16,4) DSSS Yes125 2No( 8,4) DSSS Yes250 3NoNoneYes500 SHR and PHR Spreading (64,1) DSSS

DSSS proposal update Doc: IEEE g Sensitivity Vs Data Rate For C(32,4), sensitivity is dBm applying coherent detection, while for C(16,1), sensitivity is -115dBm (PER<=10 -2 ) So the overall gain degradation of C(32,4) to C(16,1) is only about 1dB, while data rate doubled.

DSSS proposal update Doc: IEEE g Preamble Design C(64,1) is more robust than C(32,1) to spread the SHR and PHR. However, long header spread code may mean long duration period of SHR and PHR and lower network data rate. The following figures are relation of Rate vs PSDU lengths

DSSS proposal update Doc: IEEE g Preamble Design (cont’d) It’s more obviously the network data rate decrease to about half when PSDU length is shorter than 100 octets.

DSSS proposal update Doc: IEEE g Non-Coherent Detection In solution 2, the main advantage of C(16,1) for Mode=0, is that conjunction differential encoding, it allow non-coherent detections. While use (N,4) code, the receiver may not use non- coherent detection in RateMode = 1,2.

DSSS proposal update Doc: IEEE g Conclusion Suggest to use the solution 1 for united ones on 780MHz and 915MHz The following figure is reference modulator diagram for united solution 1

DSSS proposal update Doc: IEEE g Thank you