Abstract: In a transmission system comprising a transmitter coupled via a transmission channel to a receiver. The transmitter comprises a channel encoder for deriving encoded symbols from source symbols. The receiver comprises a channel decoder for reconstructing the source symbols from the signal received from the transmission channel. According to the present invention, the transmitter comprises a separate encoder for coding and transmitting a coding property used in the channel encoder to the receiver. The receiver is arranged for receiving the encoded coding property from the transmission medium, and the separate channel decoder is arranged for decoding the encoded coding property. The coding property provided by the separate channel decoder is passed to a code property setting component in the channel decoder for setting the coding property of the channel decoder.

Abstract: A portable electronic device has a keypad for entering alphanumeric characters including a plurality of single contact keys and a multi-way shift key. A character is entered by actuating a single contact key (2) alone or in combination with the multi-way shift key (3). The multi-way shift key (3) may be a four-way rocker switch, with each single contact key having five character labels, four of which are arranged to indicate the direction in which the rocker switch should be actuated to enter the corresponding character.

Abstract: On a paging receiver visual symbols are visually reproduced, relative to one another as in a two-dimensional scene, under the control of a message received.

Abstract: A prioritized buffer for the Medium Access Control (MAC) layer for multimedia applications, in particular wireless Asynchronous Transfer Mode (ATM) in which reservation based TDMA is performed on the basis of control data frames (CDFs), is formed by an addressable memory system which is divided into sequential equal-sized pages for storing respective data packets or ATM cells having the same number of bytes. The memory system includes a tag register for storing tags associated with the respective pages, each tag indicating whether the associated page is empty or full, a shadow register for storing conflict-free updates from the tag register, and a page register for storing pointers to the lowest free or unoccupied page.

Abstract: A method of despreading a GPS spread spectrum signal received at a mobile unit MSl with assistance from a base station BS1 includes (a) receiving and despreading GPS signals at the base station and deriving GPS signal information therefrom; (b) estimating the location of the mobile unit; (c) modifying the OPS signal information so as reflect the GPS signal characteristics as would be observed at the estimated location of the mobile unit; (d) transmitting the GPS signal information from the base station to the mobile unit; (e) generating replica signals containing PRN codes corresponding to those of the GPS signal using the modified GPS signal information; and (f) performing a correlation of the GPS signal and the replica signals in order to acquire the GPS signal.

Abstract: A radio receiver comprises frequency translation means(20, 21, 22) for frequency down converting an input signal to an intermediate signal, digital channel selection filtering means including at least one analogue-to-digital converter(ADC)(32, 33), the ADC comprising an over-sampling quantizer(Q1, Q2) having a plurality of dynamically selectable quantization levels, and means(30, 31, 36) responsive to the characteristics of the input signal for adjusting the resolution of the ADC to the characteristics of the input signal. The ADC may comprise a Sigma-Delta ADC. The resolution may be adjusted by altering the over-sampling rate and/or selecting the number of quantization levels to handle the prevailing interference and the wanted signal.

Abstract: A antenna arrangement comprising a multiband antenna having at least one feed point; a multiplexer, the multiplexer comprising reciprocal networks and including at least one output coupled to the at least one feed point of the multiband antenna, the multiplexer further comprising at least one input for receiving at least one signal at a first frequency, wherein the coupling between the at least one feed point and the at least one output of the multiplexer has a substantially negligible impedance.

Abstract: A slotted communication mode employed in a wireless code division multiple access (CDMA) communication system includes slotted frames interspersed among normal frames, each slotted frame containing a slot during which a measurement of signal quality of transmission at a different candidate operating frequency is made by the mobile station, a leading frame portion preceding the slot, and a trailing frame portion succeeding the slot. In order to mitigate an increase in bit error rate (BER) as a result of use of the slotted mode the spreading factor (SF) of data in the leading and trailing frame portions is set to a value which is greater than that of data in the normal frames. The increase of spreading factor of data in these frame portions may be accompanied by an increase in power level therein, as a further BER mitigating factor.

Abstract: A mobile cellular telephone (100) is disclosed comprising a communications transmitter (103) and receiver (102) arranged for two-way communication with a base station (BS), and a GPS receiver (105, 106) arranged to power up in response to direct interaction between a user and the mobile phone (100) after the telephone has been switched on. In particular, the GPS receiver (105, 106) may be arranged to power up in response to the user making a call to the emergency services. Recognition by the telephone of an emergency call being made may occur when the user enters the emergency call telephone number, or one or more, but not all of the digits of the emergency call telephone number.

Abstract: A multi-channel stereo converter is described comprising stereo magnitude determining means for generating a stereo information signal (a/b; &rgr;), which represents a degree of stereo between audio input signals (L, R), and transforming means for transforming said audio signals (L, R) based on said stereo information signal (a/b; &rgr;) into at least a surround signal (S). A space mapping interpretation is presented and an audio center signal may be derived from the stereo input signals as well. The result is more flexibility in application and design, without substantial cross talk in the audio signals.

Abstract: The invention relates to a switched-mode power supplying for a varying load in consecutive cycles of an operation period. Such a varying load may be, for example, a liquid crystal display device. The switched-mode power supply comprises converting means for converting an input voltage into an output voltage and control means arranged to generate a control signal for controlling the converting means. When chip-on-glass technology is used, parasitic resistances may introduce a lag in the output voltage regulation. In order to reduce the lag of the output voltage, the control means comprises memory means for storing status information corresponding to the load level relating to the switching pattern of the converting means in consecutive cycles, and the control means are arranged to generate the control signal from the retrieved status information.

Abstract: A selective call system comprising a primary station (10) and a plurality of secondary stations (12), such as paging receivers, has provision for the primary station sending to a predetermined secondary station a qualifying call from which data, for example loyalty points, can be determined and credited to the user of a secondary station. In one embodiment, the primary station (10) receives the data and compiles a point-to-point qualifying call which includes a field containing the data and the identity code of the predetermined secondary station. Optionally, a security field and a checksum may also be included in the qualifying call compiled. The addressed secondary station (12) decodes the received qualifying call and determines the data which is stored in a non-volatile store (48) which accumulates the items of the data. The user of the secondary station is able to display the data held in the non-volatile store (48) on the secondary station's own display panel (42).

Abstract: A transmission portion of a front end for a portable communication device, in accordance with the present invention, includes a first transmission antenna coupled to a first output of a branching device for transmitting signals having a power below a threshold value. A power amplifier is coupled to a second output of the branching device. The power amplifier provides amplification to signals to be transmitted. A second transmission antenna is connected to an output of the power amplifier such that the power amplifier is switched off for transmission signals having a power below the threshold value and switched on to amplify transmission signals above the threshold value.

Abstract: A method of determining the location of a mobile radio station comprises estimating the time of arrival of a radio signal travelling between mobile and fixed radio stations and deriving the location from the times of arrival, the method of estimating the time of arrival comprising a first stage of estimation which yields a coarse estimate, the coarse estimate being used to confine the scope of a second stage of estimation which yields a more precise estimate.

Abstract: A method of rate detection at a receiving end of a code division multiple access (CDMA) system, in which system the effective data rate is variably selected at the transmitting end from an applicable rate set including a full rate and lower rates, each lower rate being the full rate divided by a different integer, and encoded symbols are repeated for the lower rates to maintain a constant apparent bit or symbol transmission rate. The data rate is first determined by a coarse decision method employing symbol repetition characteristics before any Viterbi decoding of the data, the data is de-punctured and de-repeated where required, and first Viterbi decoded at the first determined data rate, and data available from or after the first Viterbi decoding is evaluated to determine whether to select the data rate as equal to the first determined data rate.

Abstract: A transmission system comprising a transmitter comprising at least a first channel encoder for encoding source symbols into coded symbols and for setting at least one coding property thereof, and a further channel encoder for encoding the at least one coding property of the at least first channel encoder; and a receiver comprising at least a first channel decoder for deriving reconstructed source symbols from the coded symbols received from the transmitter and a further channel decoder for obtaining the at least one coding property by decoding the encoded coding property; wherein the receiver is capable of setting the at least one coding property of the at least first channel decoder according to the at least one coding property and the transmitter is capable of transmitting the encoded coding property to the receiver over a transmission channel.

Abstract: An electronic device, such as a portable telephone or PDA, has a display in the form of a pixel display with an image deflection system overlying the display. The display is controlled to provide at least two independent display images which, when displayed through the image deflection system, are individually visible from different viewing positions relative to the screen. Suitably, the image deflection system comprises a lenticular screen with the lenticles extending horizontally or vertically across the display such that the different views may be seen through tilting of the device.

Abstract: A radio device includes a receiving part (45) formed by a high-frequency selective amplifier stage (50) including a frequency selective circuit (51) having a plurality of capacitive elements (68-78), any one or more which can be selectively connected into the selective circuit in dependence on a control magnitude stored in a storage element (90) in order to tune the selective circuit to a certain frequency. Under the control of a microprocessor (92) the stored control magnitude is set to that which gives the best level measured by a level detector (98) at the output of the amplifier stage. The microprocessor varies the control magnitude to produce a series of alternate connections into the selective circuit of each and every combination of one or more of the reactive elements, receives the measurement by the level detector of the level at the output of the amplifier stage or each control magnitude, and selects the control magnitude giving the best level.

Abstract: In a receiver for FSK modulated signals, an input signal is applied to a converter (20) which mixes the input signal with a local oscillator frequency. The frequency of the local oscillator is unrelated to the frequencies of the FSK signal, resulting in a larger degree of freedom for choosing the local oscillator frequency. This oscillator frequency can e.g. be chosen to be one fourth of the sample frequency the input signal is sampled with.

Abstract: The method of dividing the frequency of electronic signal X0 includes: preloading a first predetermined value P(1:N) in an up/down counter L1 . . . LN, clocking the up/down counter L1 . . . LN by means of said electronic signal X0, detecting a state in which the up/down counter has a second predetermined value, and again preloading the first predetermined value P(1:N) in the up/down counter L1 . . . LN. The preloading operations are performed asynchronously. There is a reduction of the noise introduced in the power supply voltage of a frequency divider DIV by the periodical preloading operations of the up/down counter L1 . . . LN of this divider.