July 2003
doc.: IEEE 802.15-03/278r0
Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Preeamble Contribution for the IEEE 802.15.3a standard]
Date Submitted: [ “24 July, 2003”]
Source: [Lee W.K, S.Y.Park, Y.H. Lee, Dmitriev et al] Company [Samsung Advanced Institute of
Technology & IRE*]
Address [San14-1 Nongseo-Ri Kiheung-Eup, Yongin 449-712, Korea]
Voice:[+82-31-280-9623], FAX: [+82-31-280-9555], E-Mail:[[email protected]]
Re: [IEEE 802.15.3a Call For Proposal]
Abstract: [This document constitute a contribution of Samsung Electronics Co., Ltd.(SAIT)’s Preamble
design for the IEEE 802.15.3a high rate alternate PHY standard.]
Purpose: [PHY contribution for the IEEE 802.15.3a standard.]
Notice: This document has been prepared to assist the IEEE P802.15. 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 P802.15.
*Institute of Radio Engineering
Submission
and Electronics of RAS
Slide 1
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Samsung Advanced Institute of Technology’s
Preamble Proposal for IEEE 802.15.3a
Prepared by Dmitriev et al
[email protected]
Presented by W.K.Lee
([email protected])
Submission
Slide 2
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Contents
• Generating preamble using chaotic
sequences
• Property of chaotic sequences
• Implementation issues
• Initial conditions supporting multiple piconets
• Potential contribution
Submission
Slide 3
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Chaotic signal. What is it?
• A key notion of direct chaotic systems
– the notion of chaotic radio pulse, which is signal fragment whose
duration is longer than the quasi period of chaotic oscillations
• Benefit
– Convenient generation of multiple number of unique “Preamble
sequences” with low-cross correlation properties
• Advantages
– Simplicity of design
– Flexibility
– Enhanced possibility of multiple access
– Confidentiality
Submission
Slide 4
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Property
• 600 chaotic samples
• Autocorrelation property
Submission
Slide 5
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Digital Sequence
• 64-bits preamble using chaotic sequences
xo
1
Submission
0
0
1
1
1
0
Slide 6
1
0
1
1
0
0
1
0
1
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Method of Generation
• Generation of chaotic sequences X0, X1, X2, ….
– Uniquely determined by the mapping F
Xk+1=F(Xk).
Submission
Slide 7
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Chaotic Mapping Function
X0 = -0.9922
X1 = -0.4904
X2 = 0.7690
X3 = -0.9800
Submission
1010011011000010
1001001100101000
0001111000001010
1010011001001000
Slide 8
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Generation & Initial State (Ex.)
• The mapping rule F
3z 0  z  1 / 3

F ( z)   3
 2 (1  z ) 1 / 3  z  1
• To support 4 piconets, 4 last samples Z8 are required
– There are 32 possible initial state samples Z0 that result in 4 Z8
– That means 8 possible choice of initial states for each piconets
Submission
Slide 9
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Choices of Mapping Functions
Submission
Slide 10
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Choice of initial states
•
•
Using inverse map F-1, we can restore values Zki (i=1,4; k=0,7).
Final choice of the preamble may be done taking into account different
considerations.
– we can provide maximum of the distance between the initial states Z0i .
1-st piconet:: 0001100110011001000010001000100000000010110110001111111000011010
2-nd piconet: 0100000000000000000101010101010100000111000111000000001001011110
3-rd piconet: 1000000000000000101010101010101010001110001110001010000100101111
4-th piconet: 1110011001100110011001100110011010111011101110110011111010010011
Submission
Slide 11
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Generator Implementation
•
The implementation of sequence generator is simple
– may be done by means of some simple logic units
1,2,3  switches
4,5  shifters by one bit
6  summer
7  comparator
8  16th-bit register
9  inverter.
Submission
Slide 12
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Implementation
• FPGA (Verilog HDL 2001)
• The number of necessary cells equals to 19~41
module CMDF(clk, reset, init_data, out_data);
parameter WIDTH = 10;
input clk, reset;
input [WIDTH-1:0]init_data;
output [WIDTH-1:0]out_data;
reg [WIDTH-1:0]out_data;
always @ (posedge clk) begin
if(reset == 0)begin
out_data <= init_data;
end else begin
out_data <= (out_data << 1) + (out_data >> 1);
end
end
endmodule
Submission
Slide 13
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Chaotic Sequence Example – 128bits
S1
101001000000110100000111011101011000011010100111010100100101110010101110001
10010011101101100100001100000101100111101000011001111
S2
0001000001100001001000111110100000100101011001011110010000001111111001110000
1001101001111111101010110010000011001110111111111000
S3
1000110101110111110100001001000011011100010111111100000011000000101101001001
1010101111111011111100100110000100111001010100101010
S4
101100000001001101001010100011010010000000011001110110001101110001001010101
00010000110010001101101100011100000110100110000010010
• Selection is made according to correlation properties
– Arbitrarily chosen for a given length
– Specified by different initial values for the given map
Submission
Slide 14
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Autocorrelation property
S4
S1
Submission
Slide 15
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Cross-correlation property
Xcorr(S1, S4)
Xcorr(S1, S3)
Submission
Slide 16
Samsung Advanced Institute of Technology
July 2003
doc.: IEEE 802.15-03/278r0
Potential Contribution & Improvement
•
Chaotic sequences can be generated with unique correlation properties as
many as required
•
Multiple number of “Unique Sequence” can be utilized for
– Piconet Identification
– Hopping pattern characteristics
– Increased number of bands employed
•
Implementation is relatively simple
•
Flexibility
– The sequence length can be arbitrarily defined with high flexibility
– Adaptive application to various structures
Submission
Slide 17
Samsung Advanced Institute of Technology