1. doc.: IEEE 802.15-<doc#>
<month year>
<month year>
doc.: IEEE <doc#>
doc.: IEEE <doc#>
21/02/2019
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
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2. United Solutions on 915 and 780 Mhz bands
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

3. Discussion Analysis the performances for united MR-OQPSK on both bands
Find the better united solutions

4. Solution 1 1000 No (32,4) DSSS Yes 62.5 1 (16,4) DSSS 125 2
Chip Rate
(kchips/s)
RateMode
Differential
Encoding
Spreading
½ rate FEC + Interleav-ing
Data Rate
(kbps)
1000 No
(32,4) DSSS
Yes
62.5 1
(16,4) DSSS
125 2
( 8,4) DSSS
250 3
None
500
SHR and PHR Spreading
(32,1) DSSS

5. Solution 2 1000 Yes (16,1) DSSS 31.25 1 No (16,4) DSSS 125 2
Chip Rate
(kchips/s)
RateMode
Differential
Encoding
Spreading
½ rate FEC + Interleav-ing
Data Rate
(kbps)
1000
Yes
(16,1) DSSS
31.25 1 No
(16,4) DSSS
125 2
( 8,4) DSSS
250 3
None
500
SHR and PHR Spreading
(64,1) DSSS

6. Sensitivity Vs Data Rate
For C(32,4), sensitivity is dBm applying coherent detection, while for C(16,1), sensitivity is dBm (PER<=10-2)
So the overall gain degradation of C(32,4) to C(16,1) is only 1.5dB, while data rate doubled.

7. 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

8. Preamble Design (cont’d)
It’s more obviously the network data rate decrease to about half when PSDU length is shorter than 100 octets.

9. 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.

10. 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

11. Thank you