| 摘要 |
There is provided a system for providing sound to at least one user (13), comprising at least one audio signal source (17) for providing an audio signal; a transmission unit (10, 110) comprising a digital transmitter (28) for applying a digital modulation scheme in order to transmit the audio signal as audio data packets from the audio signal source via a wireless digital audio link (12); at least one receiver unit (14) for reception of audio signals from the transmission unit via the digital audio link, comprising at least one digital receiver (61); and means (16, 64, 82) for stimulating the hearing of the user(s) according to audio signals supplied from the receiver unit; wherein the transmission unit is adapted to transmit each audio data packet according to an adaptive frequency hopping scheme at a frequency selected randomly from a list of transmission channels which is selected from a given frequency hopping set of transmission channels and which is updated on a regular basis; and wherein the transmission unit comprises a channel traffic detection unit (26, 33) for measuring, on a regular basis, the power in each channel of a monitored channel set consisting of at least a part of the channels of said frequency hopping channel set at the transmission unit for providing a channel traffic value (m) for each of these channels based on the measured power, the channel traffic values forming a metric vector, an interference detection unit (26, 34) for analyzing, on a regular basis, the metric vector in order to decide whether a static interference is present and, if so, to determine the channel (x max ) corresponding to the peak channel traffic, with the analysis of the metric vector including a comparison between a maximum value (d" max ) derived from the channel traffic values and an average value (d' av ) derived from the channel traffic values; and a channel blanking unit (26, 35) for temporarily removing, if it is decided that a static inference is present, the channel corresponding to the peak channel traffic and a number of channels around said channel from the list of transmission channels. |
