Oct 2005 doc IEEE 802 15 05 0607

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Project: IEEE P 802. 15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [ICI Analysis] Date Submitted: [4 Oct 2005] Source: [Rick Roberts] Company [Harris Corporation] Address [Melbourne, Florida] Voice: [321 -729 -3018], FAX: [], E-Mail: [rrober 14@harris. com] Re: [] Abstract: [ICI Analysis] Purpose: [] Notice: This document has been prepared to assist the IEEE P 802. 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 P 802. 15. Submission 1 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a TX Filtering Induced Inter. Chip Interference (ICI) Analysis Submission 2 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Block Diagram Code 1 50% Excess BW RRC or Guassian Code 1 Low Pass 50% Excess BW RRC or Guassian BPSK MOD BPSK DEMOD Cross Correlator Auto Corr Cross Correlator Cross Corr Low Pass 4. 5 GHz LO Code 2 Submission 3 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Summary Inter. Chip Interference (ICI) at the transmitter output occurs as the chipping rate approaches the Nyquist rate. The ICI significantly increases as the chipping rate is increased beyond the Nyquist rate. This ICI impacts the transmitted code word, namely it degrades the cross correlation between previously nearly orthogonal code words and it increases the TX peak output power. The approach presented in document 15 -05 -0556 -00 -004 a is hard to evaluate because the codes are random (due to the scrambler cover code), meaning they don’t have predictable cross correlation properties except over long average. This may be problematic if we are depending upon the code to support SOP via some measure of CDMA. For this analysis I’ve used codes that have predictable properties. Submission 4 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Code Words* Source 1: -+--+--+-0 -0 --+++--Source 2: --+0+++--+-++-+0+--- * Extracted from Document 802. 15 -03/153 r 6, 2 -BOK codes for PNC 1 and PNC 2 (slide 10) Submission 5 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Root Raised Cosine Gaussian -3 d. B BW is 500 MHz Submission 6 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Chip Eye Patterns vs. Chipping Rate for Fixed 500 MHz BW RRC Gaussian 625 Mcps 500 Mcps 250 Mcps 100 Mcps Submission 7 Rick Roberts, Harris Corp

Oct 2005 Submission doc. : IEEE 802. 15 -05 -0607 -01 -004 a 8 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Note: while actual results will vary with other nearly orthogonal codewords, they will show similar degradation Submission 9 Rick Roberts, Harris Corp

Oct 2005 doc. : IEEE 802. 15 -05 -0607 -01 -004 a Conclusion It is better that the chipping rate does not exceed the Nyquist rate as determined by the pulse forming network (chipping rate filter). To do so increases the TX peak power and also starts to impact the code properties (if any). Submission 10 Rick Roberts, Harris Corp