Abstract: A method and apparatus for receiving infrared signals are provided. The circuit includes preamplifier that includes an integrator that charges based on light detected by a photodiode. The circuit includes a warning circuit that generates a warning flag when the charge on the integrator exceeds a predetermined level. To prevent the integrator from saturation, digital logic resets the preamplifier by dumping the charge on the integrator in response to the warning signal. The digital logic is also configured to reset the integrator at predetermined intervals. When the incoming signal is encoded using pulse position modulation, the interval at which the integrator is reset is the length of a single time slot in the pulse position modulation frame. A sample and hold circuit is provided to hold a previous output of the preamplifier. The difference between the previous output of the preamplifier and the current output of the preamplifier is compared with a threshold voltage to detect pulses on the incoming signal.

Abstract: A method and apparatus for detecting and indicating a collision on a wireless channel are provided. According to the method, data is transmitted over the wireless channel using pulse position modulation. The channel is monitored during each pulse position modulation frame to determine whether a pulse occurs during more than one pulse window of the pulse position modulation frame. If a pulse occurs during more than one pulse window of a pulse position modulation frame, then the devices on the wireless channel determine that a collision has occurred. A transceiver is disclosed for connecting a device to a wire-based network via a wireless connection. The device and transceiver communicate over the wireless connection using pulse position modulation. If a collision occurs on the wire-based network, then the transceiver transmits to the device a signal in which pulses are asserted during more than one pulse window of a pulse position modulation frame.

Abstract: A method and apparatus for transmitting information over a wireless connection are provided. A correlation is established between a set of symbols and a set of pulse position/signal characteristic combinations. Thus, each symbol has a corresponding pulse position and a corresponding signal characteristic. The signal characteristic may be, for example, a particular frequency, amplitude or phase. To communicate a symbol, a device generates a signal in which a tone burst is sent during the pulse position that corresponds to the symbol. In addition, at least some portion of the signal reflects the signal characteristic that corresponds to the symbol. A receiving device determines the pulse position in which the tone burst was sent and determines the signal characteristic reflected in the signal. The receiving device then determines the symbol based on the pulse position and the signal characteristic. Synchronization is improved by generating synchronization tone bursts before each pulse position modulation frame.