Abstract: A radio communication device (1) comprises a Radio Frequency (RF) unit (2) for transmitting and receiving radio signals, a link controller (3) for controlling operation of the RF unit (2) and a signal monitor (4) for monitoring signals received by the RF unit (2). A processor (5) is connected to the link controller (3) and the signal monitor (4) and a user interface (6). When it is desired for the communication device (1) to communicate with another device (9), a communication link is established in a conventional way. The signal monitor (4) is able to measure signal strength and the bit error rate (BER) of the signal received in the communication link from the other communication device (9) and outputs these to the processor (5). When the BER is unacceptably high, the processor (5) determines whether the measured signal strength has changed from very high to very low in a short period. This is indicative of the body (10) blocking the signal.

Abstract: A radio repeater (8) operates in a radio communication system (1) (such as a Bluetooth® communication system) including a mobile telephone (2) and a personal digital assistant (PDA) (3) each having a (Bluetooth®) transceiver (5,6). The repeater (8) is housed in a headset (7) incorporating an earpiece and microphone (not shown) for voice communication. The repeater (8) comprises a receive antenna (9) for receiving signals, e.g. in a band around 2.4 GHz; means (12) for shifting the frequency of the received signals by a constant frequency interval, e.g. to a band around 800 MHz; and a transmit antenna (14) for transmitting the frequency shifted signals. So, the mobile telephone (2) and the PDA (3) can communicate with each other directly using their Blue-tooth® transceivers (5,6), but, if there is no signal propagation path between them, such as when the body of a user (4) comes between them, they can receive the signals transmitted by the repeater (8).

Abstract: A receiver comprises a frequency down-conversion stage (14) for demodulating a received signal to produce an uncorrected demodulated signal (vin ), a dc offset voltage correcting circuit (22) having an output (28) for a corrected signal and a data recovery circuit (42) coupled to the output. The dc offset voltage correcting circuit (22) comprises an input for the uncorrected demodulated signal (vin), a bit slicer (30) for detecting received data, a filter (32) coupled to the output of the bit slicer for regenerating the demodulated signal less noise and dc offset, a subtracting stage (34) for subtracting the regenerated demodulated signal from a delayed version of the uncorrected demodulated signal to produce the dc offset voltage (voff) and a feedback circuit for feeding back the dc offset voltage to the bit slicer.

Abstract: A method of operating a multimode transceiver comprises simultaneously transmitting (Tx) a signal having a relatively wide output frequency spectrum and receiving (Rx) a signal having a frequency spectrum narrower than that of the output frequency spectrum, but lying in the same band. A notch is introduced by a filter (18, 19, 20) into the output spectrum of the transmitted signal at a position corresponding to the received signal. The notch is adapted in response to at least one operating characteristic of the transceiver. The notch depth and bandwidth may be a function of the received and transmitted signal strengths, the relative frequency displacements of the received and transmitted signals and of the extent to which a degradation in the transmitted signal quality due to the notch can be tolerated.

Abstract: A method of protecting an apparatus from radio frequency interference, comprises a policing terminal (PT) detecting the presence of an interfering radio terminal (16) in the protected environment and actively rendering ineffective or terminating transmissions by the interfering radio terminal. Various options can be followed by the policing terminal (PT) including (a) attempting to become the master station of a network of which the interfering terminal is a member and instructing the members to close down or (b) failing to become the master station and transmitting interference signals for at least a selected portion, for example preamble and sync, of the duration of a data packet transmitted by the interfering station.

Abstract: A receiver having a variable threshold slicer stage, comprises a demodulator (14) for providing asynchronously samples of over-sampled raw demodulated data, a shift register (60) for delaying the over-sampled data by up to 2 bit periods. Samples in stages (62, 72) corresponding to substantially the mid-points in two successive bit periods are combined to form a signal (fXn) to be applied to a bit slicer (22). A bit stream signal from the bit slicer (22) is delayed by two concatenated shift registers (30,32) for 2 bit periods and is contemporaneously applied to a clock recovery circuit (74) for producing clock signals at the data rate for sampling the delayed sliced signal (Bn-2) at the center of bit to produce an output signal (34).

Abstract: An antenna diversity receiver has a low-IF receiving mode and a diversity selection mode, and a switch arrangement for coupling one of the antennas to the IF channels when in the receiving mode, and coupling each of the channels to a different one of the antennas in the selection mode. A diversity controller compares qualities of signals received simultaneously from the different antennas during the selection mode, and controls the switch arrangement in the receiving mode, to use the better antenna. The quality measurement is carried out during reception of a carrier before a preamble to a desired signal is received, so that there is more time to obtain a better signal quality measurement and to enable better averaging over time. The channels have a polyphase filter with switchable cross coupling between the channels, so that it acts as two independent low pass filters in the selection mode.

Abstract: The present invention presents compounds that inhibit phosphodiesterase 4 having Formula (I). The present invention also provides methods of using the compounds of Formula (I) to prevent or treat asthma, atopic dermatitis, rheumatoid arthritis, inflammatory bowel disorders, pulmonary hypertension, liver injury, bone loss, septic shock, or multiple sclerosis, and to pharmaceutical compositions that contain the compounds of Formula (I).

Abstract: Diazepinoindoles of formula (I), ##STR1## wherein A is mono- to trisubstituted aryl or heteroaryl, and B is an --OR.sub.1 or --NR.sub.2 R.sub.3 group where R.sub.1, R.sub.2 and R.sub.3 are particularly hydrogen, and racemic forms, enantiomers and pharmaceutically acceptable salts thereof, as phosphodiesterase IV inhibitors, are disclosed.