June 1, 1999. 1 Morse Code, Semaphore & CD/SS™ Digital Wireless Communication Technology.

June 1, 1999. 1

Morse Code, Semaphore & CD/SS™

Digital Wireless Communication Technology

LanwaveTechnology, Inc. © 1999 2

C.E. Shannon’s Model of communication

SourceEncoding Modulation Demodulation DecodingChannel

Noise

Sender Receiver

Transformation usinga Coding Scheme

A Priori Informationon Coding method

•The Shannon Limit: maximum number of bits/sec = W log2(1 + S/N)

Signal in Bits/sec Recover Signal

LanwaveTechnology, Inc. © 1999 3

Importance of Spectrum Spreading

•Capacity-maximizing Signal density functions Pi(f) over available bandwidth W, as a function of frequency f, is the “filling” of the noise density function N(f), such as the situation under uniform gravity. Total volume of the liquid is proportional to the available transmitter power.

Bandwidth

N(f)P3(f)

P2(f)

P1(f)

W

Shannon’s water filling illustration

LanwaveTechnology, Inc. © 1999 4

Telegraph & Semaphore..The first form of digital wireless communication

Morse Code:•(26+10+..) alphabet of dots and dashes•typically short, irregular length•low bandwidth requirement•binary amplitude yields a high noise margin, &•high tolerance to phase, time & amplitude jitters•poor error correction capability

Semaphores:•same idea•low bandwidth channel•long range, low cost•many drawbacks

LanwaveTechnology, Inc. © 1999 5

SATURN Wireless Modem Chip

Telegraphing

Framing

Protocol

Symbol to alphabet (PN) code translation

Recognition Encryption Error control

Network flow control

LanwaveTechnology, Inc. © 1999 6

Telegraph with Color Filtering What is CD/SS™ ?

..110100110111000111101011000111100010101..

110 011 000 111 101 100 000

* Code Division/Spread Spectrum, or CD/SS is a registered trademark of Lanwave Technology, Inc.

LanwaveTechnology, Inc. © 1999 7

Lanwave 1-bit DSP CoreBenefits of Code Division Spread Spectrum (CD/SS™)

“Morse Code” modem - 8 symbol alphabet - Alphabet selection optimized by DSP criteria - >10dB processing gain for Part 15 compliance

1-bit DSP allows non-linear RF design- Class C power amplifier - No

automatic gain control - No I-Q mis-matching issues

Simplified timing reference - Independent clocks in each node

LanwaveTechnology, Inc. © 1999 8

Implementation

Each symbol (alphabet) is assigned a 32-bit color code (8x32chip PN sequence)

Symbol boundary alignment - Search&Lock - programmable thresholds

Color separation - Minimum Hamming distance - parallel processing design

Framing, Error Protection, Encryption - TDD, Parity/BCH, (11,3)MRL Encryptor - programmable

LanwaveTechnology, Inc. © 1999 9

Bandwidth Efficiency

frequency

t

Direct Sequence Spreading

(DSS)Code Division/Spread Spectrum

(CD/SS™)

1

0

0

111

010

001

green

red

blue

frequency

F(pn)

F(/pn)

** F(pn) is the Discrete Fourier Transform (DFT) of the pseudo random code pn.

Advantage over Direct Sequence Spread Spectrum

LanwaveTechnology, Inc. © 1999 10

Fast Synchronization

frequency

time

Frequency Hopping Spread Spectrum

(FHSS)Code Division/Spread Spectrum

(CD/SS™)

Advantage over Frequency Hopping Spread Spectrum & FH/TDMA

Sequence Broken

Resync

Black Out

• Long BLACK OUT (seconds) on FCC required FH PN sequences• Dramatically increasing cost, as environment becomes noisy

frequency

Sequence Broken

time

LanwaveTechnology, Inc. © 1999 11

Code Overlapping

frequency

Code Division with Multiple Access

(CDMA)Synchronous CD/SS™ *

(S-CD/SS™)

frequency

time

• Wide variations in TOA increase DSP complexity, reducing performance• Synchronous CD/SS™ controls code overlap to fractions of chip time

time

Time of Arrival (TOA) varies from the lack of source timingsynchronization

* CD/SS Filtering of Secondary Color Code (mix of Primary Color).** Technology in next generation Lanwave CD/SS™ processors only.

Advantages over traditional CDMA

LanwaveTechnology, Inc. © 1999 12

Framing for Flexible Protocol Data Encapsulation, Encryption, Error and Flow Control

Preamble: 18 symbols of “000”. 54 bit time.

UID/UST field 18 symbols (Fully encrypted)UID: User definable ID field - 24 bit time. 22-bit user programmable.UST: Command & Status. 24-bit (3 bytes) per frame.CRC: 6-bit Error detection code for the UID/UST subframe.

Subframes: 18 encrypted symbolsData: 48 bits CRC: 6-bit

Preamble UID & UST Subframe 1 Subframe 4Subframe 2 Subframe 3

110 011 000 111 101 100 000..

LanwaveTechnology, Inc. © 1999 13

Optimized for Voice TransmissionTime Division Duplexing & Minimizing Acoustic Echo

Transmit Frame

Transmit FrameReceive Frame

Receive Frame

3ms

6ms

handset receiver output

telco line signal

Transmit Frame

Receive FrameBase Unit

Handset

Voice transmission delay = Receive frame (6 subframes) + G1 + G2 + Transmit preamble & control (2 subframes)= 4.313 ms

G1 G2

LanwaveTechnology, Inc. © 1999 14

Telephone Benefits

Multiple handsets Audio Noise Reduction Frequency & Space Diversity Advanced Power Management Configurable Networking Architecture Timers, CPU Clock Gen, Wakeup Monitor

allowable by the SATURN chip architecture

LanwaveTechnology, Inc. © 1999 15

Multiple Client Protocol

Subgroups

Star, Bus, Point-to-point, Point-to-multi point, Any-to-any hail (Page Mode)

IndividualizedExtensions

Intercom

Base-line access,with 3-way conference

Paging

Ad-hocnetworking

Intercominitiation.. hail

LanwaveTechnology, Inc. © 1999 16

Circuit and Packet ConnectionsRJ-11 to PSTN with PCM to E1/T1, or RJ-45 to Internet with Voice over TCP/IP

Huh ? ..CSMA, isochronous, GAP-II, DECT, xDSL, I-Node, A-Node, U-plane, NDIS, SWAP, TAPI, 802.11, NWK, DLC, Q.931, TDMA, ISDN, ATM..

It simply means..

..your phone is now Internet friendly.

LanwaveTechnology, Inc. © 1999 17

Diversity Antennato counteract indoor Multipath Fading (Lanwave Technical note AN-7)

Fading results from reflection off walls, forming peaks and valleys from EM wave superimposition

Time, Space and Frequency varying, mobility dependent, forms non-stationary random processes

Calculation units provided in SATURN simplified antenna selection allowing for 4-bit MCU implementation.

Hardware synchronized switching control

LanwaveTechnology, Inc. © 1999 18

Hybrid Hopping

Avoid frequency selective noise sources such as other cordless phones, microwave oven, home network

Smart hopping (with a-priori knowledge) using SATURN hardware assistance, PLL channel selection by MCU

With FCC 15.247 spreading requirement met, simplified hopping by using deterministic sequence, reducing resynchronization delay from jamming

Simple algorithm suitable for 4-bit MCU

LanwaveTechnology, Inc. © 1999 19

Advanced Noise Reduction

QuietcodeSticky CounterSearch & LockDual AntennaDistance SensingPower ControlConjugate FrequencySmart Channel SearchHybrid Hopping

Hardware

XXX

XX

SoftwareXXXXXXXXXXXXXXXXXXXXXXXX

PerceptionXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

For detail see Lanwave Technical note AN-5, AN-6

LanwaveTechnology, Inc. © 1999 20

Typical Cordless Telephones

CPU4-bit

ReceiverMic46/49MHz

Single chipCT controller

CPU4-bit

ReceiverMic

LCD

SATURNL9002VX

CODECRF

circuit

battery mgmt

46/49/900MHzAnalog

900MHz/2.4GHzDigital Phone

LanwaveTechnology, Inc. © 1999 21

Observations

Digital design is a science, RF is an art. Analog problem sticks over time.. Loops cost money, gates are free (almost).

Over doing DSP hurts power Use link layer DSP for noise control “Its the multipath, stupid!” Testing dominate silicon cost

eventually

Wireless System Design for Consumer Electronics

LanwaveTechnology, Inc. © 1999 22

This Picture Contains a “$” Sign

LanwaveTechnology, Inc. © 1999 23

Filtering of your eyethe Digital Filtering of Color, is CD/SS™ Technology

Do you see the “$” sign?

there is an “S”in yellow, an “N” in light gray. When viewing under a pure red filter, the blue and green turns to black, to review an arrow pointing NE at the one o’clock direction forming “$”.

LanwaveTechnology, Inc. © 1999 24

Lanwave Technology, Inc.Your Wireless Connection

Contact Lanwave (USA) for detailsTel: (408)-253-3883, Fax: (408)-253-6630

Local (Asia) representatives Japan distribution: Sanshin Electronics

Tel: (81)-3-54847380

Taiwan: Tonsam CorporationTel: (886)-2-2651-0011, Fax: (886)-2-

2651-0033Hong Kong & China:

Dynax Telecom Ltd. Tel: (852)-2481-0223, Fax: (852)-2481-0826