Abstract: A sliding-window multi-carrier communication system is described, wherein the carriers are orthogonal in a local sense, but not necessarily in a global sense. In one embodiment, the system allows a reduction of the length of the basis function time as compared to conventional OFDM systems. In some circumstances, the symbol time can be reduced almost to the basis function length even though the delay spread from channel-to-channel is significant. In one embodiment, a discrete Fourier transform DFT is used in the sliding-window receiver. In one embodiment, the DFT produces M outputs (one output for each of M channels) for each time-domain input. In one embodiment, the DFT produces outputs for M channels from N samples, where N is a basis function length. In one embodiment, the sliding-window receiver provides an adjustable basis-function length. In one embodiment, the basis-function length can be separately selected for each channel.

Abstract: A sliding-window multi-carrier communication system is described, wherein the carriers are orthogonal in a local sense, but not necessarily in a global sense. In one embodiment, the system allows a reduction of the length of the basis function time as compared to conventional OFDM systems. In some circumstances, the symbol time can be reduced almost to the basis function length even though the delay spread from channel-to-channel is significant. In one embodiment, a discrete Fourier transform DFT is used in the sliding-window receiver. In one embodiment, the DFT produces M outputs (one output for each of M channels) for each time-domain input. In one embodiment, the DFT produces outputs for M channels from N samples, where N is a basis function length. In one embodiment, the sliding-window receiver provides an adjustable basis-function length. In one embodiment, the basis-function length can be separately selected for each channel.

Abstract: A powerline network physical layer that allows multiple nodes to communicate digital data at high speed, with low error rates, using electrical powerlines in a home or office is described. The physical layer provides multiple channels by using Frequency Division Multiplexing (FDM). Each FDM channel is independent and separately modulated to carry data using Differential Binary Phase Shift Keying (DBPSK) or Differential Quadrature Phase Shift Keying (DQPSK). The error rate on each FDM channel is monitored and the separate channel are used according to an error rate criterion. If a channel is presenting an error rate that is too high, the channel is either disabled, ignored, or reconfigured into a reduced-capacity mode that provides an acceptable error rate.

Abstract: An apparatus for adding cordless handset capability to an existing corded telephone is disclosed. A cordless handset replaces the corded handset of the existing corded telephone. The cordless handset includes a wireless transmitter, a wireless receiver, a battery to provide power to the cordless handset, and a battery charging connector. A cradle insert forms a substitute handset cradle over the original handset cradle of the corded telephone. The substitute handset cradle receives the cordless handset when it is not in use. Charging contacts are provided on the substitute handset cradle to charge the batteries of the cordless handset. The substitute cradle allows operation of the hook switch of the corded telephone when the cordless handset is placed into the substitute cradle.