Abstract: A radio receiver comprising a compensator arranged to compensate for intersymbol interference in a signal received at the receiver and a configurator arranged to configure the compensator, wherein the compensator comprises a programmable filter and the configurator is capable of configuring the filter in a first mode to operate as an ISI equaliser or in a second mode to implement a RAKE finger set.

Abstract: A receiver for a telecommunications system, wherein the receiver is capable of using a plurality of available alternative receiver sub-systems and the receiver comprises selection means for selecting one of the plurality of receiver sub-systems for use in processing a received signal according to conditions of the propagation channel through which the received signal was received.

Abstract: A device and method of combining a first version of an information block and a second version of the information block is disclosed. The method comprises calculating, prior to combining the first and second versions of the information block, a scaling factor to be applied in combining the first and second versions of the information block to produce a scaled combined information block.

Abstract: A device and method of combining a first version of an information block and a second version of the information block is disclosed. The method comprises calculating, prior to combining the first and second versions of the information block, a scaling factor to be applied in combining the first and second versions of the information block to produce a scaled combined information block.

Abstract: A receiver for a telecommunications system, wherein the receiver is capable of using a plurality of available alternative receiver sub-systems and the receiver comprises selection means for selecting one of the plurality of receiver sub-systems for use in processing a received signal according to conditions of the propagation channel through which the received signal was received.

Abstract: A radio receiver comprising a compensator arranged to compensate for intersymbol interference in a signal received at the receiver and a configurator arranged to configure the compensator, wherein the compensator comprises a programmable filter and the configurator is capable of configuring the filter in a first mode to operate as an ISI equaliser or in a second mode to implement a RAKE finger set.

Abstract: Apparatus for classifying a ray is disclosed, wherein the ray is received at a code division multiple access receiver. The apparatus comprises: means for receiving a neighbouring cell list comprising at least information concerning scrambling codes used by, and timing information concerning at least one neighbouring cell; means for selecting a cell from the neighbouring cell list, the cell having associated therewith one or more scrambling codes; means for determining whether the number of cells in the neighbouring cell list exceeds a threshold; means responsive to a positive determination for attempting to classify the ray to the selected cell without utilising means for mixing a received signal with a scrambling code; and means responsive to a negative determination for mixing a received signal with a scrambling code used by the selected cell to provide a mixed signal, and for examining the mixed signal to determine if the ray originates from the cell.

Abstract: A method of classifying a ray is disclosed, the ray being received at a code division multiple access receiver. The method comprises: determining if a timing characteristic of the ray falls within a predetermined range of a timing characteristic of a ray classified to a given cell; in response to a positive determination, mixing a received signal with a scrambling code used by the given cell to provide a mixed signal; and examining the mixed signal to determine if the ray originates from the given cell.

Abstract: Apparatus for classifying a ray is disclosed, wherein the ray is received at a code division multiple access receiver. The apparatus comprises: means for receiving a neighbouring cell list comprising at least information concerning scrambling codes used by at least one neighbouring cell; means for selecting a scrambling code used by a given neighbouring cell; means for mixing a received signal with the selected scrambling code to provide a mixed signal; and means for examining the mixed signal to determine if the ray originates from the given neighbouring cell.

Abstract: An input signal is mixed with a scrambling code and with an OVSF code, and then accumulated over a period of time equal to one symbol of the pilot channel before being reset. The resultant complex signals are mixed with the conjugate of complex signals provided by a pilot pattern generator, with the result being fed to a delay line (22). A multiplier multiplies the complex value at a location P(n) in the delay line (22) by the conjugate of a complex value at another location P(n+k), and provides the resulting complex number (which is a complex vector whose phase is a coherent measurement of the phase rotation occurring between the symbols corresponding to the two locations) at an output (27). The real part of the complex signal provided at the output (27) is provided to a first combiner (30), and the imaginary part is provided to a second combiner (31). These combiners (30, 31) also receive corresponding signals from all of the other fingers (not shown) of the rake receiver.

Abstract: A radio receiver (30) comprises an ADC (13) including a clip counter. The power of digitised signals provided by the ADC (13) is estimated by a power estimator (31), and an ideal gain value is computed from the power so estimated by a gain computation device (32). Gain computation signals are fed to a gain control input of an amplifier (11) via an LPF (33). A saturation detector (34) is connected to a clip counter output of the ADC (13), and to a control input of the LPF (33). The saturation detector (34) is arranged when saturation of the ADC is detected to reduce the gain setting value by at least two steps, by which the gain of the amplifier is immediately reduced. A detector detects the Doppler frequency of signals received and accordingly determines the size of the drop in amplification which is effected when saturation of the ADC (13) is detected. The gain reduction may be 3 dB under very low Doppler shift conditions and 12 dB under very high Doppler shift conditions.

Abstract: An input signal is a complex vector whose phase is a coherent measurement of the phase rotation occurring between two separated symbols of a received CDMA signal. A processing block (30) provides a first signal showing the magnitude and the sign of the imaginary part of the input signal, and a second signal showing the magnitude and sign of the real part of the input signal to an initialisation block (31). A quadrant determination block (32) examines the signs of the signals to determine the quadrant in which the phase of the input signal exists. A comparator block (33) determines if the magnitude of the first signal is greater than or equal to the magnitude of the second signal. If a negative determination is made, the magnitude of the first signal is doubled in a multiplication block (35) to form a multiplied signal, and a counter incremented, initially from zero. The comparator block (33) then determines if the multiplied signal is greater than or equal to the magnitude of the second signal.

Abstract: Apparatus for classifying a ray is disclosed, wherein the ray is received at a code division multiple access receiver. The apparatus comprises: means for receiving a neighbouring cell list comprising at least information concerning scrambling codes used by at least one neighbouring cell; means for selecting a scrambling code used by a given neighbouring cell; means for mixing a received signal with the selected scrambling code to provide a mixed signal; and means for examining the mixed signal to determine if the ray originates from the given neighbouring cell.

Abstract: Apparatus for classifying a ray is disclosed, wherein the ray is received at a code division multiple access receiver. The apparatus comprises: means for receiving a neighbouring cell list comprising at least information concerning scrambling codes used by, and timing information concerning at least one neighbouring cell; means for selecting a cell from the neighbouring cell list, the cell having associated therewith one or more scrambling codes; means for determining whether the number of cells in the neighbouring cell list exceeds a threshold; means responsive to a positive determination for attempting to classify the ray to the selected cell without utilising means for mixing a received signal with a scrambling code; and means responsive to a negative determination for mixing a received signal with a scrambling code used by the selected cell to provide a mixed signal, and for examining the mixed signal to determine if the ray originates from the cell.

Abstract: An input signal is mixed with a scrambling code and with an OVSF code, and then accumulated over a period of time equal to one symbol of the pilot channel before being reset. The resultant complex signals are mixed with the conjugate of complex signals provided by a pilot pattern generator, with the result being fed to a delay line (22). A multiplier multiplies the complex value at a location P(n) in the delay line (22) by the conjugate of a complex value at another location P(n+k), and provides the resulting complex number (which is a complex vector whose phase is a coherent measurement of the phase rotation occurring between the symbols corresponding to the two locations) at an output (27). The real part of the complex signal provided at the output (27) is provided to a first combiner (30), and the imaginary part is provided to a second combiner (31). These combiners (30, 31) also receive corresponding signals from all of the other fingers (not shown) of the rake receiver.

Abstract: A method of classifying a ray is disclosed, the ray being received at a code division multiple access receiver. The method comprises: determining if a timing characteristic of the ray falls within a predetermined range of a timing characteristic of a ray classified to a given cell; in response to a positive determination, mixing a received signal with a scrambling code used by the given cell to provide a mixed signal; and examining the mixed signal to determine if the ray originates from the given cell.

Abstract: A code space is divided into three windows of different sizes. The position of the strongest ray in the code space is called the “normal”. Two search correlators are allocated to window (1), four search correlators to window (2), and two search correlators to window (3). This allocation of the search correlators is based on an estimation of the probability of a new ray appearing in the relevant portions of the code space, relative to the normal. To begin with, the four search correlators allocated to the window (2) are controlled to occupy the normal, 0.5 chips, 1.0 chips and 1.5 chips respectively. After dwelling at their positions for 512 chips (the dwell time) each search correlator is moved four steps (two chips) along the code space. Each of the search correlators dwells at its new position for 512 chips, before again moving two chips further along the code space.

Abstract: An input signal is a complex vector whose phase is a coherent measurement of the phase rotation occurring between two separated symbols of a received CDMA signal. A processing block (30) provides a first signal showing the magnitude and the sign of the imaginary part of the input signal, and a second signal showing the magnitude and sign of the real part of the input signal to an initialisation block (31). A quadrant determination block (32) examines the signs of the signals to determine the quadrant in which the phase of the input signal exists. A comparator block (33) determines if the magnitude of the first signal is greater than or equal to the magnitude of the second signal. If a negative determination is made, the magnitude of the first signal is doubled in a multiplication block (35) to form a multiplied signal, and a counter incremented, initially from zero. The comparator block (33) then determines if the multiplied signal is greater than or equal to the magnitude of the second signal.

Abstract: A rake receiver (40) includes, in a finger, a subtractor (31) which is arranged to detect the difference in power between early and late samples E1P, L1P of a signal being received at a particular position in the code space. A subtractor (33) operates in the same way on an adjacent finger. The receiver includes multipliers (32, 34) which operate to reduce the amplitude of signals provided to the subtractors (31, 33) if it is detected that the fingers are close together in the code space. The fingers are thereby opposed from moving together and the signals from the fingers thereby continue to be processed separately. Data for controlling the multiplication factor of the multipliers (32, 34) is stored in a look-up table (41).