RF Triangulation: Indoor/Outdoor Location Finding Chip Giovanni Fonseca David Fu Amir Ghiti Stephen Roos Design Manager: Myron Kwai Overall Project Objective: Design a Radio-Frequency indoor/outdoor navigation system, utilizing the existing wireless infrastructure.

Project Description Use existing wireless signals to calculate one’s location when GPS is not available. The RF Triangulator will use existing infrastructure to act as an indoor/outdoor local positioning system Using distances calculated from signal to noise ratios from 3 or more wireless access points it will be possible to determine one’s coordinates to within 1 meter.

Motivation & System Integration It will be able to quickly provide your current location and aid in path finding. Can be used by outdoor venues such as amusement parks, tourist areas or college campuses to provide interesting information. To be used indoors to privately locate resources or navigate unfamiliar buildings Our chip can be integrated into handheld computers, watches, cell phones or shopping carts for locations ranging from large theme parks to office buildings.

Our Vision

Triangulation Algorithm Our chip will solve for the simultaneous solution of 3 circle equations – done by the Calc module

Calculations for Calc

Other Components Top Three: Tracks and ID’s best (closest) three signals utilizing distance and access point MAC address. Calculates moving average of signal distance to reduce noise. Caches four recently seen signals. SRAM: Can be loaded with local access point locations and updated as you move.

Dataflow

Design Process Split design into 4 pieces: lookup table, top three, calc and the fpu modules Original specifications for the chip included 16-bit floating point calculations and a waypoint finder utilizing a trig lookup in RAM that could show the direction to your desired location. Size and complexity constraints reduced floating point numbers to 12-bits and eliminated waypoint calculation 1KB SRAM = 48,000+ transistors =>1800bit SRAM Reduced transistors by receiving distance as an input instead of calculating it.

Floorplan Evolution

Lookup Verification 22: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO=xxxxxxxxxxxx, x= x, y= x, f=0, d=0, o=0, clk=0 23: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 0, y= 0, f=1, d=1, o=0, clk=1 24: r=0, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 0, y= 0, f=1, d=1, o=0, clk=0 25: r=0, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 0, y= 0, f=0, d=1, o=0, clk=1 26: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 0, y= 0, f=0, d=1, o=0, clk=0 27: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 0, y= 0, f=0, d=0, o=0, clk=1 28: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 0, y= 0, f=0, d=0, o=0, clk=0 59: r=0, w=1, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=0, d=0, o=0, clk=1 60: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=0, d=0, o=0, clk=0 61: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=1, d=1, o=0, clk=1 62: r=0, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=1, d=1, o=0, clk=0 63: r=0, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=0, d=1, o=0, clk=1 64: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=0, d=1, o=0, clk=0 65: r=1, w=0, rst=1, mI= , xin= 9, yin= 9, mO= , x= 9, y= 9, f=0, d=0, o=0, clk=1 Rise Time: 78.2 ps Fall Time: 66.1ps

Top Three Verification *OP: t = 260 INPUTS: [ ID = 0000aaaabbbb SNRr = 80 clk|rst = (1|1) ] LOOKUP: [ ID = 0000aaaabbbb (X,Y) = ( 20, 30) (SNRt,SNRr) = ( 200, 80) ] NEWROW: [ ID = 0000aaaabbbb (X,Y) = ( 0, 0) (SNRt,SNRr) = ( 0, 80) ] ROW A : [ ID = (X,Y) = ( 0, 0) (SNRt,SNRr) = ( 0, 0) R(1) ] ROW B : [ ID = 0000aaaabbbb (X,Y) = ( 20, 30) (SNRt,SNRr) = ( 200, 300) R(1) ] ROW C : [ ID = (X,Y) = ( 0, 0) (SNRt,SNRr) = ( 0, 0) R(0) ] SAMPLA: [ Sample 1 = 0 Sample 2 = 0 Sample 3 = 0 Sample 4 = 0 Average = 300 ] SAMPLB: [ Sample 1 = 300 Sample 2 = 300 Sample 3 = 300 Sample 4 = 300 Average = 300 ] SAMPLC: [ Sample 1 = 0 Sample 2 = 0 Sample 3 = 0 Sample 4 = 0 Average = 300 ]

Calc Verification >./fpu_optest -md -single Input– A: (3009) B: (5) --Results– prod: (1) quo: (601) rem: (4) Done

Issues Encountered Slow or incomplete rise times from lack of buffering especially in SRAM Triangulation algorithm conversion to hardware was difficult Registers became larger than expected Underestimated bus sizes especially in top three with several 48+ bit buses

Pin Specifications PIN COUNT : Input – clk, Output – 12-bit X, reset, 12-bit Y write, = 24 output pins 48-bit MAC, 12-bit X, InOut – Vdd!, Gnd! 12-bit Y, 12-bit Distance = 87 input pins Total Pins = 115

Part Specifications Top Three: 29,322 trans. 3 x FPU Add/Sub Units: 4500 trans. Registers: trans. Muxes & Computation: 8718 trans Area: 602x512 u 2 Density:.095 trans/u 2 FPU Adder: 2,160 trans. Prenorm 866 trans. Postnorm 988 trans. Adder 306 trans. Area: 136x76 u 2 Density:.21 trans/u 2 FPU Mult/Divide: 5,601 trans. Prenorm 1032 trans. Postnorm 1527 trans Mult/Divide 3042 Area: 180x195 u 2 Density:.16 trans/u 2 Lookup: 15,018 trans. Control Registers & Muxes: 2094 trans. Control Logic: 163 trans. Computation: 611 trans. SRAM: 12,150 trans. Area: 210x240 u 2 Density:.3 trans/u 2 Calc: 21,379 trans. 2 x FPU Add/Sub Unit: 2160 trans. 1 x FPU Mult/Div Unit: 5601 trans. 1 x Shifter: 206 trans. 1 x Comparator: 282 transistors. FSM Logic: 1106 transistors 25 x 12-bit Registers: 6600 trans. total 8-1,6-1,4-1,2-1 Mux Sets: 3264 Area: 200x x200 u 2 Density:.08 trans/u 2

Chip Specifications Total Chip: 65,719 transistors Area: 712x871 u 2 Density: trans/u 2 Aspect Ratio: 1.13 Speed: 100Mhz

Layout Masks

Conclusion A good floorplan is essential for a good layout To ensure ExtractedRC results are ok buffering and simulations on schematics are key Group communication is very important