Patent ID: 8494457
Filing Date: 2013-07-23
Classification: H04B,H04L

Abstract:
1. A transmitter for a wireless communications system, comprising: a subcarrier mapper configured to receive a plurality of input symbols, configured to assign the plurality of input symbols to N logical subcarriers, configured to map the N logical subcarriers to N available physical subcarriers out of N an inverse fast fourier transform (IFFT) processor configured to perform an inverse fourier transform on the N a parallel to serial converter configured to convert an output of the IFFT processor to a serial output stream, wherein the N wherein the subcarrier mapper is further configured to assign at least one pilot signal to at least one of the plurality of logical subcarriers, wherein the IFFT processor is further configured to modulate each of the available physical subcarriers with data from a corresponding logical subcarrier, wherein the subcarrier mapper is further configured to set an input data signal corresponding to each of the plurality of unavailable physical subcarriers to zero, wherein the subcarrier mapper is further configured to define a plurality of clusters in the discontiguous bandwidth segments, each of the clusters comprising a plurality contiguous subcarriers, configured to define an adaptive modulation and coding (AMC) subchannel comprising a plurality of contiguous clusters extending over a plurality of contiguous symbols, configured to allocate a first plurality of subcarriers within the AMC subchannel as pilot subcarriers such that the pilot subcarriers are distributed uniforml across the AMC subchannel, and configured to allocate a second plurality of subcarriers within the AMC subchannel as data subcarriers, and wherein pilot subcarriers in an AMC channel are offset by two subcarriers in adjacent symbols.