Patent ID: 9641376
Date: 2017-05-02
CPC Classifications: H04L

Claim:
1. A base station for communicating data using Orthogonal Frequency Division Multiplexed (OFDM) symbols to a first receiver and a second receiver, comprising: modulation circuitry configured to modulate first and second input data symbols onto sub-carrier signals of OFDM symbols, which are intended for receipt by the first and second receivers, respectively, based on proximity of the first and second receivers to the base station, both the first and second input data symbols being modulated onto the sub-carrier signals of the OFDM symbols, the modulation being performed for both the first and second input data symbols using a common modulation scheme; and transmission circuitry configured to form a baseband signal including the OFDM symbols and to transmit the baseband signal, wherein the first input data symbols are encoded more robustly than the second input data symbols such that when the baseband signal including the OFDM symbols is received at the first receiver, the modulated second input data symbols in the OFDM symbols appear to the first receiver as noise, wherein the first receiver is farther away from the base station than the second receiver, wherein the common modulation scheme is an N-QAM modulation scheme, where N=2 to the (A+B)th power, A being a first value which is a number of bits that are used to select a constellation point in a modulation scheme used for modulating the first input data symbols, and B being a second value which is a number of bits that is used to select a constellation point in a modulation scheme used for modulating the second input data symbols, and wherein the modulation circuitry is configured to modulate data representing signaling data indicating when both of the first and the second input data symbols are modulated on the OFDM symbols.