Patent ID: 7426249
Filing Date: 2008-09-16
Classification: H03M

Abstract:
1. An apparatus comprising: a radio receiver configured to wirelessly receive radio signals determined from packets of OFDM data transmitted in a wireless network, each packet of OFDM data including one or more fields coded at a pre-defined relatively low data rate and including information on the data rate of the remainder of the packet, and the remainder of the packet coded at the data rate indicated in the one or more fields; an analog-to-digital converter to provide digital samples; and a receive signal path coupled to the analog-to-digital converter, the receive signal path includes a discrete Fourier transformer and a configurable Viterbi decoder, the decoder including: a branch metric generator with an input accepting a coded signal and generating branch metrics; an ACS subsystem coupled to and accepting the branch metrics from the metric generator; a survivor memory subsystem coupled to and accepting input from the ACS subsystem, the survivor memory subsystem having a plurality of outputs, each providing a decoded version of the coded signal decoded to a distinct decision depth; and such that the Viterbi decoder is able to decode the signal to one of a plurality of decision depths by selecting one of the memory unit outputs, wherein the Viterbi decoder is first set to decode at the pre-defined relatively low data rate, and as a result of decoding the one or more fields is set to decode at the data rate of the remainder of the packet indicated in the one or more fields.