Reduced latency channel-estimatio

Abstract

A receiver and associated method for receiving an OFDM signal. The signal comprises a series of OFDM symbols, each symbol comprising a plurality of sub-carriers, each sub-carrier being modulated by one or more data bits encoded with an error-correcting code. The receiver comprises: a first error-correcting decoder (250), adapted to decode sequentially the data bits of a received first OFDM symbol; a re-encoder (255), arranged to receive decoded bits from the first decoder and adapted to re-encode a leading portion of the decoded bits; a mapper (225), arranged to receive the re-encoded leading portion of bits from the re-encoder, map these bits to a corresponding subset of the plurality of sub-carriers, and thereby estimate a modulation symbol that was applied to each sub-carrier of said subset, by the transmitter; a channel estimator (260), adapted to produce a channel estimate by comparing the sub-carrier modulation symbols estimated by the mapper with the corresponding sub-carriers actually received by the receiver; and an equalizer (215), adapted to process the received signal to remove distortions introduced by the transmission channel, using the channel estimate, wherein the re-encoder (255) is adapted to begin re-encoding the leading portion of the bits before a trailing portion of the bits has been decoded by the decoder (250).

Description

technical field [0001] The invention relates to a receiver and method for receiving OFDM signals, in particular to channel estimation and equalization processing at the receiver. Specifically, it is related to wireless networking based on the IEEE802.11 family of standards. Background technique [0002] Wireless networking based on IEEE 802.11a / g is designed for fixed indoor use (in Wireless Local Area Networks or "WLANs", also known as "Wi-Fi" networks). However, standardization bodies have decided to re-use the physical layer (PHY) from IEEE802.11a for vehicle-specific networks. Specifications for this enhanced standard are defined in an amendment known as IEEE802.11p. The new standard is expected to find application in areas such as Intelligent Transportation Systems (ITS), for both safety and non-safety related purposes. The difference between IEEE802.11a and IEEE802.11p lies mainly in the Media Access Control (MAC) layer. [0003] The IEEE802.11a physical layer spec...

AI Technical Summary

Problems solved by technology

The aim is that a delayed version of a signal that has undergone interference cancellation based on improved channel estimation will exhibit a higher signal-to-noise ratio and thus a lower bit error rate after decoding

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