Weekly Group Meetingon 06-08-2008

WiMAX Kernel Definitions

By

Assad Saleem

2

WiMAX Transceiver

ScrambleChannelcoding

Inter-leaving

MappingPilot

InsertionIFFT

AppendCP

Symbolshaping

XMT

DescrambleChannel

DecodingDe-

interleavingDemapping

Channelequalization

FFTRemove

CP

FrequencyOffset

compensation Filtering

RCV

CHANNEL

Complex-valuedprocessing

Bit-basedprocessing

3

Kernels for WiMAX Tx/Rx baseband Processing

Kernels

• Append/Remove Cyclic Prefix

• IFFT/FFT

• Sub-channelization/ De-subchannelization

• Frequency Offset estimation

• Frequency Offset correction

• Pilot Insertion

• Channel Equalization

• Synchronization

• Symbol Mapping/ De-mapping

• Channel Coding/Decoding

• Scramble/ Descramble

• Interleaving/De-interleaving

• Receive/Decimation filter

4

Hardware considerations for Programmable WiMAX Processing

Kernel Operation MIPS

Frequency Offset estimation

Autocorrelation, complex argument calculation: CMAC, cordic algorithm

100

Frequency Offset correction

Rotor: table look-up, CMUL

480

Synchronization Crosscorrelation in time domain: CMAC, absolute maximum or in freq domain: FFT, CMUL, IFFT, absolute maximum

400

Receive/Decimation filter FIR/IIR filter: CMAC 1200

Channel estimation Frequency domain correaltion with known pilot symbol: FFT, CMUL

400

Channel equalization One complex multiplication for each sub-carrie: CMUL

64

Demodulation FFT 480

5

WiMAX Job overview

• Max. bit rate: 46.6 Mbit/s• Sample rate: 13.8MHz• FFT size: 256• Symbol rate: 43kHz

with radix-2 FFT• Processing: 44 Mbf/s• Memory bandwidth: 256 Msample/s• Memory size: 1536 sample

with radix-4 FFT• Processing: 11 Mbf/s• Memory bandwidth: 133 Msample/s• Memory size: 1280 sample

• Equivalent DSP MIPS: 440

Thank You.