PDF《DWA Wireless GmbH, Germany》

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2 sub-chips per chip C basic chip rate of coding scheme is unchanged ? Addition per sub-chip for multivalue encoding C no other changes of PSSS model May

2005 Andreas Wolf, DWA Wireless Slide

6 doc.: IEEE 15-05-0216-04-004b Submission No modification of the basic PSSS model: PSSS 250-400

868 MHz C BPSK/ASK (20/32 bit/s/Hz) Base sequence2 Selected

20 shifted sequences Input Data

20 32(x2) Bit-to-Symbol Mapper

0 /

1 bits ? -1 /

1 x BPSK / ASK modulator Sequence with

32 chips (64 subsymbols) per Symbol Symbol-to-Chip Mapper Combiner 32(x2)

20 sequences Addition of per-row multiplication result plus precoding Pulse shaping Tc/2 ? No increase of Tx complexity in real-world implementation C - Oversampling used for baseband filtering to achieve PSD compliance anyhow - No change in number of chips per symbol C no increase in coding table sizes ? Simpler baseband filter sufficient due to lower chiprate, see PSD at Appendix. ? No change in Rx processing required ? Similar performance, see Appendix. May

2005 Andreas Wolf, DWA Wireless Slide

7 doc.: IEEE 15-05-0216-04-004b Submission Signal Flow ? The preamble (eight times repeated c0) and the SFD (one time inverted c0), are BPSK modulated. ? The Phy header and PHY payload are PSSS encoded and ASK modulated. ? Both signals have same chip duration and passes same pulse shaping. Pulse Shaping Square root raised cosine preamble and SFD May

2005 Andreas Wolf, DWA Wireless Slide

8 doc.: IEEE 15-05-0216-04-004b Submission PSSS Codes form Coding Table in Draft Standard for Preamble ? We propose to use Sequence

0 = c0, 4/16 times repeated for 868/915 MHz, instead of the barker code. ? Preamble will then be more similar to the other Phys. c0 May

2005 Andreas Wolf, DWA Wireless Slide

9 doc.: IEEE 15-05-0216-04-004b Submission Comparision Actual/New Proposed Preamble Length of Proposed Preamble ? The Sequence

0 is repeated 4/16 times for 868/915 MHz. Same duration of 320?s for both preambles.

128 4

1 32 Sequence

0 for

868 MHz

512 16

1 32 Sequence

0 for

915 MHz

208 8

2 13 Barker Code preamble # of chips # of repeating # of codes Code length yes no

32 Chip long

1 2 # of needed FIR in Rx yes yes DC free Sequence

0 Barker Code May

2005 Andreas Wolf, DWA Wireless Slide

10 doc.: IEEE 15-05-0216-04-004b Submission Summary ? We propose to use PSSS 250-400 instead of PSSS 206-440 for ETSI. ? We propose also to use the new preamble base on Sequence C0 for similar design compared to the other Phys. May

2005 Andreas Wolf, DWA Wireless Slide

11 doc.: IEEE 15-05-0216-04-004b Submission Appendix ? PER versus Eb/N0 PSSS 206-440 ? PER versus Eb/N0 PSSS 250-400 ? PSD PSSS 250-400 ? Correlative detection of current Barker code based preamble ? Correlative detection of new proposed preamble May

2005 Andreas Wolf, DWA Wireless Slide

12 doc.: IEEE 15-05-0216-04-004b Submission PER Performance PSSS 206-440

868 MHz (BPSK/ASK) C Discrete Exponential Channel, 250ns RMS Delay Spread Comparison to COBI: ? Over

11 dB performance benefit over COBI16+1 C Expected even higher performance benefit against COBI16 ? Estimated 15-18 dB performance benefit over COBI8 C Little if any performance benefit over 868MHz FSK chips for COBI8 C PSSS

206 kbit/s C COBI16+1

235 kbit/s >

10000 Channel, no Rake receivers May

2005 Andreas Wolf, DWA Wireless Slide

13 doc.: IEEE 15-05-0216-04-004b Submission PER Performance PSSS 250-400

868 MHz (BPSK/ASK) C Discrete Exponential Channel, 250ns RMS Delay Spread Comparison to PSSS 206-440