7-May-2007 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [DecaWave Proposal for TG3c Alternative PHY] Date Submitted: [2007-May-7th] Source: [Brian Gaffney, Michael Mc Laughlin] Company [DecaWave] Address [25 Meadowfield, Sandyford, Dublin 18, Ireland] Voice:[+353 87 688 2514], FAX: [none], E-Mail:[michael.mclaughlin@decawave.com, brian.gaffney@decawave.com] Re: [Response to Call for Proposals 15-07-0586-02-003c-tg3c-call-proposals.doc] Abstract: [Alternative PHY Proposal for TG3c] Purpose: [To assist TG3c in selecting a mm Wave PHY] 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. Gaffney, Mc Laughlin, DecaWave
7-May-2007 DecaWave 3c Proposal Gaffney, Mc Laughlin, DecaWave
Proposal Outline Single Carrier system. Low Complexity Low Power 7-May-2007 Proposal Outline Single Carrier system. Low Complexity Low Power Adaptive Phased Antenna Array to boost SNR at receiver and provide spatial multiple access Gaffney, Mc Laughlin, DecaWave
Proposed Band Plan U.S. Japan 57 59 64 66 f(Ghz) 3dB BW 1.6 Ghz 7-May-2007 Proposed Band Plan U.S. Japan 3dB BW 1.6 Ghz 400 MHz 400 MHz 1 2 3 4 57 59 64 66 f(Ghz) ~2.2Ghz Separation Gaffney, Mc Laughlin, DecaWave
Base Mode Modulation: 1.4Gbps 7-May-2007 Base Mode Modulation: 1.4Gbps RS Encoder (63,55) Symbol Interleaver Systematic Convolutional Code R 1/3 8-QAM Constellation Mapping Gaffney, Mc Laughlin, DecaWave
Modulation Scheme 8-QAM Allows for Non-Coherent reception 7-May-2007 Modulation Scheme 8-QAM Used in the V.29 modem standard due to resilience to phase noise. Higher bandwidth efficiency than QPSK. More resilient to phase noise and power amplifier problems than higher order constellations (16-QAM). Allows for Non-Coherent reception Only two levels R1=√2, R0=1+√3 Q 001 100 101 000 010 I R1 111 110 R0 011 Gaffney, Mc Laughlin, DecaWave
Error Correction Coding 7-May-2007 Error Correction Coding Outer systematic Reed Solomon block code. Inner systematic Convolutional code. Constraint length K = 5 and rate 1/3. One information bit in produces 3 bits out (the information bit and two parity bits) which are mapped to a symbol in the 8-QAM constellation. Systematic to allow for Non-Coherent Reception for low complexity receivers File Transfer and Kiosk usage scenarios Both low complexity codes Overall coding gain of 8dB Gaffney, Mc Laughlin, DecaWave
7-May-2007 Outer Reed Solomon The systematic Reed Solomon code is over the Galois field GF(26) and is given as RS(63,55) Input of 55 symbols creates 8 parity symbols for a rate 0.87 code Systematic gives the option of ignoring the parity symbols in low complexity receivers Currently used in IEEE 802.15.4a standard Interleaved output before input to inner code improves performance by separating burst errors at the receiver Gaffney, Mc Laughlin, DecaWave
Convolutional Code: Rate 1/3, K=5 7-May-2007 Convolutional Code: Rate 1/3, K=5 + + Generator Polynomial: g1=208, g2 = 278, g3 =328. Gaffney, Mc Laughlin, DecaWave
Convolutional Code Rate 1/3 Low complexity 7-May-2007 Convolutional Code Rate 1/3 Low complexity With K=5, there are only 16 possible states. 8 branch metrics need to be calculated per symbol Gaffney, Mc Laughlin, DecaWave
7-May-2007 Convolutional Code Systematic code gives the option of ignoring the parity bits Important for Non-Coherent receiver. To be covered later. However, systematic codes are known to perform worse than non-systematic. The combination of this systematic code with this constellation mapping approaches the performance optimal non-systematic code with a Gray coded constellation Gaffney, Mc Laughlin, DecaWave
8-QAM Constellation 001 100 101 000 010 111 110 011 7-May-2007 Gaffney, Mc Laughlin, DecaWave
Our 8-QAM versus Gray Coded 7-May-2007 Our 8-QAM versus Gray Coded Gaffney, Mc Laughlin, DecaWave
Data Modes Four Data Modes: Base mode 1.4Gbps 7-May-2007 Data Modes Four Data Modes: Base mode 1.4Gbps High data rate mode 2.8Gbps Very High data rate mode 4.2Gbps Low rate (67Mbps) back channel mode obtained by sending a direct sequence code Gaffney, Mc Laughlin, DecaWave
Base Mode – 1.4Gbps Base mode Inner and Outer coding 8 QAM modulation 7-May-2007 Base Mode – 1.4Gbps Base mode One bit per symbol. Pulse Repetition Frequency (PRF) = Bandwidth (B) Data rate = 0.87*B Gbs Inner and Outer coding Interleaver in between 8 QAM modulation Gaffney, Mc Laughlin, DecaWave
7-May-2007 Base Mode – 1.4Gbps Gaffney, Mc Laughlin, DecaWave
High Rate Mode : 2.8Gbps RS Encoder (63,55) Symbol Interleaver 7-May-2007 High Rate Mode : 2.8Gbps RS Encoder (63,55) Symbol Interleaver Systematic Convolutional Code R 1/3 Puncture 8-QAM Constellation Mapping Gaffney, Mc Laughlin, DecaWave
High Data Rate Mode – 2.8Gbps 7-May-2007 High Data Rate Mode – 2.8Gbps High Data Rate mode Two bits per symbol Punctured Base mode PRF = B Interleave RS output Data rate = 2*0.87*B Gbs Not transmitted From convolutional coder s1 s2 s3 s4 s5 s6 Gaffney, Mc Laughlin, DecaWave
High Data Rate Mode – 2.8Gbps 7-May-2007 High Data Rate Mode – 2.8Gbps Gaffney, Mc Laughlin, DecaWave
Very High Rate Mode : 4.2Gbps 7-May-2007 Very High Rate Mode : 4.2Gbps RS Encoder (63,55) 8-QAM Constellation Mapping Gaffney, Mc Laughlin, DecaWave
Very High Data Rate Mode – 4.2Gbps 7-May-2007 Very High Data Rate Mode – 4.2Gbps Very High Data Rate mode No convolutional code Reed Solomon RS(63,55) Interleave RS output Data rate = 3*0.87*B Gbs Gaffney, Mc Laughlin, DecaWave
Very High Data Rate Mode – 4.2Gbps
Low Data Rate Mode – 67Mbps 7-May-2007 Low Data Rate Mode – 67Mbps Low data rate back channel mode. Length 21 Ipatov ternary sequence. +00−++−0+0+−+++++−−0− Golay Merit Factor of 5.3 Gives the option of 67Mbs (base mode) or 133Mbs (high data mode) which is more resistant to errors Gaffney, Mc Laughlin, DecaWave
Non Coherent Reception 7-May-2007 Non Coherent Reception The Non Coherent receiver is ideal for File Transfer or Kiosk modes The systematic bit decides which “ring” the transmitted symbol is on. Therefore, by using a simple energy detector receiver we can decode the systematic bit from any base mode signal. The Outer Reed Solomon code then gives some optional error correcting capabilities Gaffney, Mc Laughlin, DecaWave
Non Coherent Reception 7-May-2007 Non Coherent Reception to RS decoder from antenna BPF Gaffney, Mc Laughlin, DecaWave
Non Coherent Reception 7-May-2007 Non Coherent Reception Used with a directional antenna, we can achieve a data rate of 1.4Gbs at short range Enables a very low cost, very low power, implementation Ideal for integration into media players, phones, cameras etc. Gaffney, Mc Laughlin, DecaWave
Non Coherent Reception – 1.4Gbps 7-May-2007 Non Coherent Reception – 1.4Gbps Gaffney, Mc Laughlin, DecaWave
7-May-2007 Phased Antenna Array We propose using a phased antenna array to boost the signal to noise ratio at the receiver input and provide spatial multiple access. The phased antenna array can adapt to any direction of arrival (assuming omni directional elements) The phased antenna array offers a low complexity solution Gaffney, Mc Laughlin, DecaWave
7-May-2007 Phased Antenna Array + Gaffney, Mc Laughlin, DecaWave
7-May-2007 Phased Antenna Array For omni directional antenna elements, the phased antenna array can achieve a high gain in any given direction. For example, ten elements (uniform linear array) can give a gain of 10dBi To achieve higher gains, directive elements need to be applied which require some physical alignment of Tx and Rx The non-coherent mode could have a single highly directive element and assume the user will align the Tx and Rx Gaffney, Mc Laughlin, DecaWave
7-May-2007 Hidden Node Problems Major problem with directive antenna systems is finding Nodes. To combat this problem, we propose using a single element mode. For omni-directional antenna elements, we can now “see” in every direction. For directive antenna elements, we can only “see” in the direction we can adapt in. Gaffney, Mc Laughlin, DecaWave
7-May-2007 Hidden Node Problems However, the path loss is so high at 60Ghz, a very weak signal is received when we are not using the antenna array gain The Solution: Compensate for the lack of antenna array gain at Tx and Rx by spreading the signal to obtain an equal or higher processing gain Gaffney, Mc Laughlin, DecaWave
Ternary Spreading Sequence 7-May-2007 Ternary Spreading Sequence Ipatov Sequence Perfect Periodic Autocorrelation properties. Allows for accurate channel estimation for Channel Matched Filtering (CMF) and Antenna Array adaptation. Used in 802.15.4a For example, a length 183 sequence is equivalent to an antenna array gain of approximately 22.2 dBi Many such sequences allows separate piconets to co-exist Example length 183 Ipatov Sequence: +−−−+0+−−−−−++−−+++++++−−++0+−+−+−+−−00−−+−+−++−−++−−+−0−−−++−−0−++−0−−+++−+++−−+−+−−+−+++++0−−++−−++−+−−−0+0+++0+−0−−−−−+−++−−0++++−+−−−−+++−+−+−−++−++−+0−++++−+−++++−++−+++++++−+−−+ Gaffney, Mc Laughlin, DecaWave
Ternary Spreading Sequence 7-May-2007 Ternary Spreading Sequence Periodic Auto Correlation of Length 183 Ipatov Sequence Gaffney, Mc Laughlin, DecaWave
Ternary Spreading Sequence 7-May-2007 Ternary Spreading Sequence With the perfect autocorrelation we can obtain an excellent estimate of the channel for the Channel Matched Filter (CMF) Send 16 times before each packet Gaffney, Mc Laughlin, DecaWave
Interference & susceptibility 7-May-2007 Interference & susceptibility All out of band interference filtered out. Adjacent channel interference is filtered out. However, power amplifier backoff will affect this and will be addressed fully at future meetings. Co-channel interference is avoided by spatial multiple access. Narrowband interference rejection with digital notch filter Tones can be detected at the A/D output. A simple notch filter either at the input or output of the matched filter can then remove this completely with no loss in performance (if notch is narrow enough). Gaffney, Mc Laughlin, DecaWave
Link Budget (LOS) Parameter Low Base High Rate Very High Rate 7-May-2007 Parameter Low Base High Rate Very High Rate Non Coherent PHY-SAP Payload Bit Rate (Rb) 67Mb/s 1.4Gb/s 2.8Gb/s 4.2Gb/s Average Transmit Power 10dBm Transmit Antenna Gain 10dBi Center frequency (fc) 60GHz Path loss at 1 meter 68dB Receive Antenna Gain 0dBi Average noise power per bit -69.3dBm -82.5dBm -79.5dBm -77.7dBm Noise Figure 8dB -74.5dBm -71.5dBm -69.7dBm Minimum Eb/N0 for AWGN channel 2.5dB 4.6dB 8.4dB 8.5dB 22.6dB Shadowing link margin 1dB Implementation Loss 2dB Tolerable path loss 34.25dB 28.6dB 22dB 20.2dB 10.9dB Maximum operating range (d = 10 PL/10n,n=2) 51.6m 27m 12.6m 10.2m 3.5m Gaffney, Mc Laughlin, DecaWave
Link Budget (NLOS) Parameter Base High Rate 7-May-2007 PHY-SAP Payload Bit Rate (Rb) 1.4Gb/s 2.8Gb/s Average Transmit Power 10dBm Transmit Antenna Gain 13dBi Center frequency (fc) 60GHz Path loss at 1 meter 68dB Receive Antenna Gain Average noise power per bit -82.5dBm -79.5dBm Noise Figure 8dB -74.5dBm -71.5dBm Minimum Eb/N0 for AWGN channel 4.6dB 8.4dB Shadowing link margin 5dB Implementation Loss 2dB Tolerable path loss 30.6dB 24dB Maximum operating range (d = 10 PL/10n,n=2.5) 16.7m 9.1m Gaffney, Mc Laughlin, DecaWave
Link Budget Summary 51.6m 27m 12.6m 10.2m 4.7m 7-May-2007 Link Budget Summary 51.6m 27m 12.6m 10.2m 4.7m Bit Rate Channel Model Range for 10-2 PER 67Mbps LOS 51.6m 1.4Gbps 27m 2.8Gbps 12.6m 4.2Gbps 10.2m NLOS 15.5m 8.4m Gaffney, Mc Laughlin, DecaWave
Base Mode: 1.4Gbps CM 1.3 (LOS) 7-May-2007 Base Mode: 1.4Gbps CM 1.3 (LOS) Gaffney, Mc Laughlin, DecaWave
Base Mode: 1.4Gbps CM 2.3 (NLOS) 7-May-2007 Base Mode: 1.4Gbps CM 2.3 (NLOS) Gaffney, Mc Laughlin, DecaWave
Base Mode: 1.4 Gbps CM 3.1 (LOS) 7-May-2007 Base Mode: 1.4 Gbps CM 3.1 (LOS) Gaffney, Mc Laughlin, DecaWave
7-May-2007 High Data Rate CM 1.3 Gaffney, Mc Laughlin, DecaWave
Performance Summary Bit Rate Channel Model Range for 10-2 PER 7-May-2007 Performance Summary Bit Rate Channel Model Range for 10-2 PER 1.4Gbps CM 1.3 33m CM 2.3 10.5m CM 3.1 23.5m 2.8Gbps 14.8m Gaffney, Mc Laughlin, DecaWave
Summary of our proposal 7-May-2007 Summary of our proposal 8-QAM modulation scheme 4 Data rates Base mode of 1.4Gps obtained with outer RS (rate 0.87) and inner convolutional (rate 1/3) coding High data rate mode of 2.8Gps obtained by puncturing base mode signal Very high data rate mode of 4.2Gps obtained by using only RS code Lower rate for back channel using Direct Sequence code Systematic code developed specifically for the 8-QAM constellation which enables a Non-coherent receiver architecture Node discovery and channel adaptation with omni directional antenna mode with spreading gain from long ternary sequence Gaffney, Mc Laughlin, DecaWave
Advantages Low Power, Low Complexity solution 7-May-2007 Advantages Low Power, Low Complexity solution Constellation resilient to RF impairments Simple Non-coherent mode Ideal for low cost receiver e.g. for media player Single carrier potential common signalling mode operation More resistant to multipath Ternary sequences and omni-directional antenna mode allows easy node discovery and channel estimation Gaffney, Mc Laughlin, DecaWave