The invention relates to a method for the compensation of interference in a signal generated by discrete multitone modulation. The signal generated by discrete multitone modulation has a multiplicity of carrier frequencies, and each carrier frequency has a signal vector. An error signal vector is generated from a reference signal vector, which is a signal vector from the multiplicity of signal vectors. The error signal vector is added to each of the remaining signal vectors of the multiplicity of signal vectors for the purpose of compensating for interference. Each of the signal vectors of the multiplicity of signal vectors, except for the reference signal vector, is assigned a set of adjustable coefficients by which the error signal vector is multiplied prior to the addition.
A circuit arrangement for compensating for disturbances in a signal generated by means of discrete multitone modulation includes a multiplicity of adder circuits that are supplied with an error signal vector that is not used for transmitting data via the transmission channel. The multiplicity of adder circuits adds the error signal vector to at least one signal vector to generate an error-corrected signal vector. The circuit arrangement can also include at least one further multiplicity of adder circuits that are supplied with a further error signal vector, the at least one further multiplicity of adder circuits adding the respective further error signal vector to the at least one signal vector to generate a progressively error-corrected signal vector. The circuit arrangement further includes at least one multiplicity of multiplier circuits that precede the at least one multiplicity of adder circuits and multiply the respective error signal vector by adjustable coefficients.
A base station implementing physical layer automatic repeat request includes a transmitter and a receiver. The transmitter has a physical layer transmitter for receiving data, formatting the received data into packets transmitting the packets and retransmitting packets in response to failure to receive a corresponding acknowledgment for a given packet; an acknowledgment receiver for receiving the corresponding acknowledgment; and an adaptive modulation and coding controller for collecting retransmission statistics and adjusting the particular data encoding/modulation using the collected statistics. The receiver has a physical layer receiver for demodulating the packets; a combiner/decoder for buffering, decoding and detecting packet errors; and an acknowledgment generator for generating an acknowledgment for each packet if that packet has an acceptable error rate.
A method for physical automatic repeat request by a subscriber unit. A physical layer at the transmitter receives data and formats the received data into packets having a particular encoding/data modulation. The physical layer contains n channels which transmit the packets and retransmits packets upon failure to receive a corresponding acknowledgment for a given packet. An adaptive modulation and coding controller in the transmitter collects retransmission statistics and adjusts the particular encoding/data modulations using the collected statistics.
