Abstract:
A mobile phone antenna comprising a belt which is adapted to be worn by a user and which comprises an antenna arrangement which in use is coupled to the mobile phone transceiver.
Abstract:
The present invention extends the Rake architecture as discussed in co-pending patent application number 9316989.5 in which the need for a set of Rake fingers covering a continuous range of delays in one chip steps is removed. The apparatus only comprises a small number of Rake fingers, one or more of which is assigned at any given time to perform a searching operation. Whenever the searching Rake finger or fingers finds a path with higher energy than the current lowest Rake finger the roles of the Rake finger are exchanged.
Abstract:
In a correlation method local interference cancellation is carried out based on the significant paths of the strongest received signal. These are the paths that may cause interference to the weaker signals and the interference cancellation is carried out at relevant parts of the weaker signals. This saves computational time in comparison with cancellation carried out over all points of the signals.
Abstract:
An interpolator for a discrete time signal is provided, which performs the steps of identifying a plurality of interpolation points which interpolation points are symmetrically temporarily displaced about a central reference point of a plurality of discrete time samples of a signal for which interpolated signal samples are to be calculated at the interpolation points, determining a plurality of impulse response coefficients appertaining to the interpolating function at each corresponding sampling time of the said plurality of signal samples, and contemporaneously calculating a plurality of interpolated discrete time signal samples corresponding to the interpolation points in combination with a pre-addition of at least one pair of discrete time signal samples.
Abstract:
Code Division Multiple Access (CDMA) based on Direct Sequence Spread Spectrum (DSSS) permits good multipath diversity by the use of the so-called rake receiver. When multipath codes are sent over the same link (to increase the transmission rate for that link without altering the basic transmission format) multiple rake receivers would normally be required. This invention involves the rake combining operation prior to code correlation in order to make only a single rake processor necessary. This affords significant savings in complexity.
Abstract:
A cellular mobile radio system in which power control is applied and in which measurement of the relative paths losses between base station and mobiles are used to compute the stability condition. In one system, mobiles are arranged to transmit a common known sequence at different times and the base stations are arranged to correlate against this sequence throughout the data transmission burst period to measure the signal levels from all mobiles within range. Base stations log the levels and times of reception. The data is aggregated over the network interconnecting the base stations to a common point. At this common point the timings of the unknown mobile signal reception peaks are matched to those of the known in other base stations in order to identify the mobile associated with every correlation peak.
Abstract:
A packet radio communication network comprises a plurality of packet radios which are adapted to communicate with one another, in which transmissions from each packet radio are made in time slots and each packet radio is adapted to receive transmissions made in each of the time slots. Each of the packet radios is allocated a particular time slot but is able to transmit in a plurality of the time slots by transmitting a request for such transmissions to other packet radios in its vicinity, the other packet radios transmitting back to the requesting packet radio whether the requested time slots are being used by it or by one of its neighbouring packet radios.
Abstract:
A packet radio communication network comprises a plurality of packet radios which are adapted to communicate with one another, in which transmissions from each packet radio are made in time slots and each packet radio is adapted to receive transmissions made in each of the time slots. Each of the packet radios is allocated a particular time slot but is able to transmit in a plurality of the time slots by transmitting a request for such transmissions to other packet radios in its vicinity, the other packet radios transmitting back to the requesting packet radio whether the requested time slots are being used by it or by one of its neighbouring packet radios.
Abstract:
The invention relates to a frequency suppression circuit arrangement, which allows at least one selected frequency band to be suppressed by coupling the frequency suppression circuit between the input and output of an RF power amplifier. The frequency circuit in the embodiments of the invention down-converts a feedback signal derived from the amplified output signal into baseband signals. Each of the baseband signals is fed into an inverting amplifier to generate a negative baseband signal. The negative baseband signal is subsequently filtered to selectively pass the negative baseband signal. The filtered signal is subsequently up-converted into an RF signal. The up-converted RF signal is combined and provided to a coupler connected at the input of the power amplifier such that when the input signal is amplified by the RF power amplifier any signals at the selected frequency can be suppressed.
Abstract:
A method of transmission comprises receiving at a first destination (D1), a transmission from a first source (S1); determining from the transmission from the first source, the maximum permitted additional interference subject to which the first destination can still communicate; sending an acknowledgement of the transmission and including in the acknowledgement an indication of the determined maximum permitted additional interference. A second source (S2) determines whether it has received the transmission from the first source, or the acknowledgement from the first destination, at a power level lower than that of the maximum permitted additional interference given in the indication; and if so, the second source sends a transmission to a second destination (D2), which at least partially overlaps in time, communication between the first source and first destination.