Abstract: An antenna diversity method and a corresponding communication device are disclosed that may be used in wireless LAN receivers. An AGC (Automatic Gain Control) unit controls a gain when processing signals received from antennae. A periodical switching process is performed between at least two antennae. During this periodical switching process, signals from each of the antennae are received alternately. The gain obtained by processing each received signal by means of the AGC unit is monitored and the obtained gain is compared with a predetermined threshold value. When for one of the at least two antennae the gain is below the predetermined threshold value, the periodical switching process is stopped and the antenna used at the time when stopping the periodical switching process is selected. This technique may provide an improved antenna diversity of low complexity, high performance and a short settling time.

Abstract: A WLAN (Wireless Local Area Network) receiver is provided that provides at least two acquisition units and at least two tracking units. The acquisition units perform a synchronization acquisition process, and the tracking units perform a synchronization tracking process. The acquisition units are arranged for being operated sequentially while the tracking units are arranged for being operated simultaneously. In an embodiment, frequency and phase error correction may be performed separately, and those units that operate at higher sampling rates may be located before lower-rate units. The synchronization process may include data-aided as well as non data-aided algorithms.

Abstract: A signal pre-processing device particularly in wireless LAN devices is provided that comprises an AGC (Automatic Gain Control) unit, an ADC (Analog-to-Digital Converting) unit and a normalization unit. The AGC unit amplifies a received analog input signal and outputs an amplified analog signal. Further, it automatically controls an amplification gain when amplifying the analog input signal. The ADC unit receives the amplified analog signal, converts it into a digital signal and outputs the digital signal. The normalization unit is receives the digital signal, applies a normalization function to the digital signal and outputs the normalized digital signal. Thus, less precise AGC units can be used, thereby reducing production costs as well as the size and complexity of the AGC unit. Further, shorter circuit development times are obtainable.

Abstract: Therefore, the object of the invention is to utilize the unused channel capacity of the television channel even more optimally for additional signals. Both on the transmitting, as well as the receiving side, the clock pulses for video and audio data to be additionally transmitted are generated from the FBAS useful signal by counting, weighting and decision-making, both signals being separately digitized, buffered, and compressed before being superimposed upon on the useful video signal. Subsequent to the same clock pulse generation, the steps follow in the reverse order on the receiver side. The implementation can be carried out on the transmitter side using additional equipment, on the receiver side by computer software or additional devices installed in the conventional TV set. The application can be carried out for any additional video and sound signals. A preferred special application is a community picture broadcast similar to a slide presentation.