參數(shù)資料
型號: L64781
廠商: LSI CORP
元件分類: 消費家電
英文描述: SPECIALTY CONSUMER CIRCUIT, PQFP100
封裝: PLASTIC, QFP-100
文件頁數(shù): 94/164頁
文件大?。?/td> 2003K
代理商: L64781
Channel Estimation and Equalization
2-15
2.13 Channel Estimation and Equalization
The output from the common phase-error (CPE) correction block is a
sequence of complex numbers, each describing the signal received on
one of the COFDM carriers. The numbers correspond to values, chosen
from points of the current constellation, which were used to modulate
each carrier at the modulator. Each carrier is received with unknown
amplitude and phase due to the combined effects of:
The channel through which the RF signal has passed (which, in
general, is frequency selective)
Any minor error in the FFT timing window
The purpose of the channel estimation and equalization block is to
correct these effects so that the complex numbers at its output would, if
plotted on an Argand diagram, correspond to points of the transmitted
constellation (for example, QPSK, 16-QAM, or 64-QAM) except for any
superimposed noise or interference.
2.14 Viterbi Metric Assignment and Quantization
The Viterbi metric assignment and quantization block takes in a
sequence of complex numbers, each describing the signal received on
one of the COFDM carriers, after equalization. These are the received
complex numbers chosen at the modulator for the current constellation
points, according to the coded bits to be sent. This block forms Viterbi
metrics (“soft decisions”) for each received bit. The block quantizes these
metrics and passes them on, after reordering in the deinterleaver stages,
to the associated Viterbi convolutional decoder. The use of “soft” rather
than “hard” decisions is vital to obtaining the rugged properties of
COFDM.
2.15 Inner Symbol Deinterleaver
From each received constellation point, the Viterbi metric assignment
block extracts up to six soft decisions. The symbol deinterleaver accepts
one COFDM symbol’s worth of soft decisions and reorders them
l64781.book Page 15 Friday, January 19, 2001 1:28 PM
相關(guān)PDF資料
PDF描述
L6561 0.7 A POWER FACTOR CONTROLLER, PDIP8
L6566ATR 0.8 A POWER FACTOR CONTROLLER WITH POST REGULATOR, 300 kHz SWITCHING FREQ-MAX, PDSO16
L6605D SPECIALTY CONSUMER CIRCUIT, PDSO20
L6605 SPECIALTY CONSUMER CIRCUIT, PDIP18
L6660 SPECIALTY CONSUMER CIRCUIT, PDSO24
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L64782 制造商:未知廠家 制造商全稱:未知廠家 功能描述:L64782 Single-Chip COFDM Receiver
L6480 制造商:STMICROELECTRONICS 制造商全稱:STMicroelectronics 功能描述:The L6480, realized in analog mixed signal technology, is an advanced fully integrated solution suitable for driving two-phase bipolar stepper motors with microstepping.
L64801GC-20 制造商:未知廠家 制造商全稱:未知廠家 功能描述:32-Bit Microprocessor
L64801GC-25 制造商:未知廠家 制造商全稱:未知廠家 功能描述:32-Bit Microprocessor
L64801GM-20 制造商:未知廠家 制造商全稱:未知廠家 功能描述:32-Bit Microprocessor