Submission Slide 1 doc.: IEEE g March 21, 2016 Joint DSSS Proposal for g Merged proposal : , , Michael Schmidt, 2 Y X Fu, 2 J Shen, 2 X Wang, 2 Haituo Liu, 2 L Li, 2 Z Zhao, 2 Z.F Zhao, 3 Ted Myers, 3 David Howard 1 Atmel, 2 Huawei/SIMIT/VINNO, 3 On-Ramp Wireless Supported by: John Buffington, Hartman Van Wyk, Daniel Popa, Itron Roberto Aiello
Submission Slide 2 doc.: IEEE g March 21, 2016 Bands included No bandwidth limitation in bands –780MHz (China) 779 – 787 MHz –868MHz (EU) 863 – 870 MHz –915MHz (US) 902 – 928 MHz –2450MHz (Intl) 2400 – MHz
Submission Slide 3 doc.: IEEE g March 21, 2016 DSSS benefits Better sensitivity increases range for hard to reach meters and challenging environments, especially in-building Good complement to Merge FSK Proposal Trade-off between processing gain and data rate with fixed bandwidth – long range for reduced data rate and short range for high data rate Different data rates can be obtained by simply changing the spreading gain, with same RF design
Submission Slide 4 doc.: IEEE g March 21, 2016 Modulation O-QPSK –Raised cosine shape r=0.8 GMSK –Pre-coded –Equivalent to /2 – BPSK (*) (*) for example see: Draft P c/DF3, page 45: "a) The standard supports the use of MSK/GMSK modulations with appropriate filtering and pre-coding as an alternative way of generating π/2 BPSK waveform signals for the SC PHY mode."
Submission Slide 5 doc.: IEEE g March 21, 2016 PSDU Channel Code ½ rate convolution code –Benefits Supports long frame requirements in PAR Provides larger gain compared to spreading as decrease data rate by ½ Used in IS-95 and other systems Consider interleave to improve resistance to burst interference –Interleaver Max depth of 32 information octets –Complexity Constraint length k=7
Submission Slide 6 doc.: IEEE g March 21, – 787 MHz PHY Chip rate = 500kcps Channel center frequency (MHz) –779.5, 780.5, 781.5, 782.5, 783.5, 784.5, 785.5, Spreading code –(4,4), (8,4), (16,4), (32,4) PSDU coded data rate (bps) –250k, 125k, 62.5k, 31.25k Preamble header spreading –(32,1)
Submission Slide 7 doc.: IEEE g March 21, – 870 MHz PHY Chip rate = 200kcps Channel center frequency (MHz) –863.4, 873.8, 864.2, 865, 865.4, 866, 866.6, 867,2, 867.8, 868.3, Spreading code –(4,4), (8,4), (16,4), (32,4) PSDU coded data rate (bps) –100k, 50k, 25k, 12.5k Preamble header spreading –(32,1)
Submission Slide 8 doc.: IEEE g March 21, –928MHz/ GHz PHY Chip rate = 1Mcps Channelization –400kHz channels (*) Spreading code –(32,4), (16,1), (32,1), (64,1) PSDU coded data rate –62.5k, 31.25k, 15.6k, 7.8k Preamble header spreading –(128,1) (*) 400kHz is chosen to simplify interoperability with Merged FSK proposal. Channels are overlapping, however system will choose every forth channel, in a scheme similar to
Submission Slide 9 doc.: IEEE g March 21, 2016 (N,1) - FEC Concatenation
Submission Slide 10 doc.: IEEE g March 21, 2016 (N,4) - FEC Concatenation
Submission Slide 11 doc.: IEEE g March 21, 2016 PPDU Format PHR Field –2 octets –Frame Length(11 bits) Indicate the frame length from 0 – 2047 bytes Compatible with PPDU Format of –Date Rate Field (2 bits) Indicate the spreading sequence to binary data of PSDU, RX adjust receive PN sequence according to this field –Parity Check Field (1 bit) Check the PHR field Octets: 8124~2047 Bits: PreambleSFDData Rate ModeFrame LengthReservedParity CheckPSDU Includes FCS
Submission Slide 12 doc.: IEEE g March 21, 2016 NB FH co-existance DSSS channel overlaps a group of NB channels NB must hop within DSSS channel, then both hop to next DSSS channel DSSS receiver has ability to detect NB signals
Submission Slide 13 doc.: IEEE g March 21, 2016 Example 1.2MHz DSSS and 200KHz FH (channel spacing) DSSS 1 FH1FH2FH3FH4FH5FH6 DSSS 2 FH21FH22FH23FH24FH25FH26 DSSS n FHn1FHn2FHn3FHn4FHn5FHn6