Eddy Kwon, Jay Yu, Jin-Kyu Han, Yuchul Kim, Jay Yu, Julie Lim, Zhouyue Pi, Donghee Kim Samsung Electronics Co., Ltd. Tel: ABSTRACT: This contribution provides simulation results comparing VoIP performance between Distributed Resource Channel (DRCH) and Block Hopping (BH). TITLE: VoIP Performance Comparison of DRCH and BH TSG-C WG3 RECOMMENDATION: FYI Samsung Electronics grant a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. Samsung Electronics are also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner’s standard which incorporates this contribution. This document has been prepared by Samsung Electronics to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on Samsung Electronics. Samsung Electronics specifically reserves the right to amend or modify the material contained herein and to any intellectual property of Samsung Electronics other than provided in the copyright statement above. C DATE: June 26, 2006 SOURCE:

2 Contents  Introduction  Overview of DRCH and BH  Simulation Assumptions  VoIP Performance Comparison Results of DRCH vs. BH  Summary

3 Introduction  Two different transmission schemes, DRCH (Distributed Resource Channel) and BH (Block Hopping) have been proposed for LBC mode of Rev C.  In this contribution, VoIP performance is compared between DRCH and BH.

4 Overview of DRCH and BH DRCHBH Assignments Scattered over time and frequency Continuous sub-carriers and continuous OFDM symbols Pilot (Common/Dedicated)Common pilotDedicated pilot Pilot overhead* (Resources) SIMO: % MIMO(4x4): 12.5 % SIMO: % ~ % MIMO: % ~ % Benefits Low pilot overhead High frequency diversity More accurate channel estimation More accurate interference estimation *Based on LNS proposal and QCOM’s proposal. ([1] and [2]) Power overhead can be different in case of power boosting for pilot symbols

5 Simulation Assumptions

6 Simulation Parameters Transmission bandwidth (MHz)5 Sample rate (MHz) FFT size512 Number of useful subcarriers480 (32 Guard tones) Subcarrier spacing (MHz)9.6 kHz Slot duration (ms)0.911 (8 OFDM symbols) CP/Windowing duration (  s) 6.51 / 3.26 OFDM symbol duration (  s) Antenna configurations (Tx x Rx)(1 x 2) Channel modelPed B AT speed (km/h)3 VoIP packet arrivalEvery 20 ms VoIP payload size26 bytes Channel codingTurbo code (1/5) Modulation schemeQPSK Packet encoding delay2 slots HARQ modelingIR with max. 6 sub-packet transmissions, 6 interlaces Channel estimation DRCH: IFFT/FFT in freq, Linear interpolation in time(2 slots) BH: Combining in time(6 symbols in a block), Linear in freq

7 Resource Assignment to a VoIP Packet and Pilot Structure

8

9

10

11

12

13 Summary  VoIP performance was compared between DRCH (Distributed Resource Channel) and BH (Block Hopping).  Simulation results conclude that “DRCH with common pilot” provides significant VoIP performance gain compared to “BH with dedicated pilot” in terms of required SINR, delay performance, slot usage, and short term outage rate.

14 References [1] Lucent, Nortel, and Samsung, C , “Lucent-Nortel- Samsung (LNS) proposal for Air Interface Evolution Phase 2”, 3GPP2 TSG-C WG3, May [2] Qualcomm, C R2, “UHDR Overview”, 3GPP2 TSG- C WG3, May 2006.