Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Preeamble Contributionfor 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:[wooky.lee@samsung.com] 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. *InstituteofRadioEngineeringandElectronicsofRAS Samsung Advanced Institute of Technology

2. Samsung Advanced Institute of Technology’s Preamble Proposal for IEEE 802.15.3a Prepared by Dmitriev et al chaos@mail.cplire.ru Presented by W.K.Lee (wooky.lee@samsung.com) Samsung Advanced Institute of Technology

3. Contents • Generating preamble using chaotic sequences • Property of chaotic sequences • Implementation issues • Initial conditions supporting multiple piconets • Potential contribution Samsung Advanced Institute of Technology

4. 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 Samsung Advanced Institute of Technology

5. Property • 600 chaotic samples • Autocorrelation property Samsung Advanced Institute of Technology

6. 0 1 0 1 1 0 1 1 0 0 0 1 1 1 0 1 Digital Sequence • 64-bits preamble using chaotic sequences xo Samsung Advanced Institute of Technology

7. Method of Generation • Generation of chaotic sequences X0, X1, X2, …. • Uniquely determined by the mapping F Xk+1=F(Xk). Samsung Advanced Institute of Technology

8. Chaotic Mapping Function X0 = -0.9922 1010011011000010 X1 = -0.4904 1001001100101000 X2 = 0.7690 0001111000001010 X3 = -0.9800 1010011001001000 Samsung Advanced Institute of Technology

9. Generation & Initial State (Ex.) • The mapping rule F • 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 Samsung Advanced Institute of Technology

10. Choices of Mapping Functions Samsung Advanced Institute of Technology

11. 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 Samsung Advanced Institute of Technology

12. 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. Samsung Advanced Institute of Technology

13. 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 Samsung Advanced Institute of Technology

14. Chaotic Sequence Example – 128bits • Selection is made according to correlation properties • Arbitrarily chosen for a given length • Specified by different initial values for the given map Samsung Advanced Institute of Technology

15. Autocorrelation property S4 S1 Samsung Advanced Institute of Technology

16. Cross-correlation property Xcorr(S1, S4) Xcorr(S1, S3) Samsung Advanced Institute of Technology

17. 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 Samsung Advanced Institute of Technology