1. Submission Title: [Frequency Plan and PRF Proposal for TG4a]
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Frequency Plan and PRF Proposal for TG4a]
Date Submitted: [27 April 2005]
Source: [Ismail Lakkis & Saeid Safavi, Wideband Access Inc.]
Contact: Saeid Safavi.
Voice:[ ,
Abstract: [Minimum required PRF for CMOS DS-UWB radios]
Purpose: [Clarification of relationship between minimum PRF and maximum allowed voltage level in UWB IR]
Notice: This document has been prepared to assist the IEEE P 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 P
TG4a

2. Impulse Radio-BPSK
VPeak TC
PRI
TG4a

3. Minimum PRF Requirements
BW = 520 MHz
Technology
CMOS 90nm 2.5 Vpp
CMOS 90nm 1.0 Vpp
TChip (nsec)
1.9
BW (MHz)
520
VPeak (v)
1.25
0.5
PAve (dBm)
-14
-9.4
PPeak (dBm) 12 4
PRF VPeak
1.3 8
BW = 1560
Technology
CMOS 90nm 2.5 Vpp
CMOS 90nm 1.0 Vpp
TChip (nsec)
1.9
BW (MHz)
1560
VPeak (v)
1.25
0.5
PAve (dBm)
-14
-9.4
PPeak (dBm) 12 4
PRF VPeak
11.5 72
TG4a

4. Benefits of Low PRF over High PRF
A Low PRF system has a lower implementation cost when compared to a high PRF system
Overall required receiver gain is lower for a Low PRF system. For example a 12 MHz PRF would reduce the receiver dynamic range by 7 dB when compared to a 60 MHz PRF
The ADC would run at 12 MHz instead of 60 MHz in the above example and the entire digital processor would run at a lower clock reducing the power by a factor of 5 in CMOS
Acquisition is easier to implement since with Lower PRF the sync matched filter is much smaller:
If a 12 MHz system requires a 64 pulses sync pattern, a 60 MHz system would require a sync of 320 pulses to achieve same SNR.
Since Energy per pulse is higher (7 dB in the above example), a non-coherent receiver would perform better.
TG4a

5. PLL Reference Diagram fX fComp output fX fcomp 26 2 13 19.2 24 0.8 12
Oscillator
Reference
Divider
(R)
output
XTAL
Phase Det.
LPF
VCO
Divider, N fX
(MHZ) R
(MHz)
fcomp 26 2 13
19.2 24
0.8 12 1
TG4a

6. Frequency Plan Band No. Bandwidth (MHz) Low Freq. Center Freq.
High Freq. 1
520
3224
3484
3744 2
4004
4264 3
4524
4784
Band No. 4 1 2 3 3
3.25
3.5
3.75 4
4.25
4.5
4.75 5
GHz
Note: This plan has equal margins to 3.1 GHz & 4.9 GHz frequencies
TG4a

7. The PRF The basic recommended PRF is 13 MHz.
A PRF of 26 MHz is also supported.
These PRFs can be generated from the center frequencies of the supported bands. For example, a PRF of 13 MHz may be obtained by dividing the center frequencies by 268, 308, and 348 for bands 1, 2, and 3 respectively.
It is worth mentioning that ranging precision stays unchanged when using PRFs of 13 MHz and 26 MHz (or even higher PRFs) as the effective pulse width is only affected by bandwidth not the PRF.
TG4a