Abstract: The electrical consumption of a cellular mobile telephone is reduced by using fractional-division phase-locked loops receiving a frequency reference from a fairly inaccurate quartz oscillator. Electrical consumption is also reduced by switching the output of the oscillator onto the input of the processing stage when the transmission/reception stage is inactive. The fractional-division phase-locked loops can then be deactivated.

Abstract: A method is provided for decoding a turbo-code encoded signal in a receiver. According to the method, the signal is received from a transmission channel, and the signal is digitally turbo-code decoded. Additionally, a quality information representative of conditions of the channel state estimation is dynamically determined, and the quality information is dynamically compared with a predetermined criteria for defining good or bad estimation conditions. A Maximum-A-Posteriori algorithm in the logarithmic domain is dynamically selected for good estimation conditions, or an approximation of the Maximum-A-Posteriori algorithm in the logarithmic domain is dynamically selected for bad estimation conditions. Also provided is a receiver that implements such a decoding method.

Abstract: A method for controlling frequency of a local oscillator in a DS-CDMA type receiver includes transforming a known spread spectrum signal into a sampled digital signal formed of symbols with a despreaded frequency spectrum, and determining a residual frequency error fe for each symbol including a first residual frequency error fe1. The method further includes correcting the frequency of the local oscillator with the residual frequency errors, and determining an average of absolute values of a predetermined number of successive residual frequency errors. The average is compared with a threshold, and if the average is greater than or equal to the threshold, the local oscillator frequency is corrected using an error equal to −sgn(fe1) (1/T−|fe1|), where sgn is the sign function, | | is the absolute value function and T is duration of a symbol before determining the next residual frequency error associated with the next symbol.

Abstract: A remote terminal includes a receiver stage for receiving a transmitted signal and for delivering an analog signal. The remote terminal further includes an analog/digital converter for converting the analog signal to a digital signal, and a processing stage for processing the digital signal. The analog/digital converter is a delta-sigma converter having adjustable parameters, and the processing stage includes a tuning circuit for adjusting these parameters on the fly as a function of the transmission standard, of the actual rate of transmission of the useful data, and of the actual conditions of reception.

Abstract: In a method according to the invention, N data symbols of a subscriber signal form a block. In a first method step, the block is divided into a plurality of partial blocks having Ns data symbols. The Ns data symbols are then allocated to sub-carriers and are modulated in parallel onto the various sub-carriers, the modulation being carried out for each of the sub-carriers with at least one individual code symbol. The sub-carriers are heterodyned to form a broadband carrier, so that the Ns data symbols are transmitted simultaneously. The transmission then takes place in N/Ns successive partial blocks via the radio interface.

Abstract: The method of interference cancellation in a CDMA wireless communication system comprises receiving an incident digital signal containing a user signal transmitted on a CDMA user physical channel and an interfering signal, projecting said incident digital signal onto a projection space orthogonal to the space containing said interfering signal, filtering said projected signal with a filter matched to the CDMA user physical channel for detecting the data contained in said user signal.

Abstract: A quality of service on transmission channels in a digital transmission system is assessed. A turbo coding is carried out in a turbo coder at the transmitter end for channel coding. A turbo decoding is carried out in a turbo decoder with soft-decision output signals at the receiver end. The quality of service is determined from the variances of the soft-decision output signals from the turbo decoder. If a MAP (maximum a posteriori) symbol estimator is used at the receiver end, the quality of service is determined from the variance &sgr;2LLR of the log-likelihood ratio LLR of the soft-decision output signals from the turbo decoder. The variances &sgr;2LLR are used to calculate the bit error rate as a measure of the quality of service. An RCPTC (Rate Compatible Punctured Turbo Code) is used as the turbo code for the method and in the device for assessing the quality of service.

Abstract: In a method for transmitting data in a digital transmission system given packet-switched service, for purposes of channel coding, a turbo-coding is performed in a turbo-coder at the sender side and a turbo-decoding with soft decision output signals is performed in a turbo-decoder at the receiver side. To trigger an ARQ, the channel quality is estimated by a parameter estimation method; the variances of the soft decision output signals at the turbo-decoder are determined; the correctness or respectively, defectiveness of the transmitted packet is inferred from the channel quality and the variances; and a retransmission of at least a part of defective packet is triggered. In the retransmission of the information of a defective packet, at least part of the information suppressed by the dotting in the precious transmission is sent. This additional information is [. . .] inserted into the already existing information at the receiver side, and this complete information is decoded again.

Abstract: In a method for packet transmission using an ARQ protocol on transmission channels in a digital transmission system, for channel coding, turbo coding is carried out in a turbo coder at the transmitter end and turbo decoding is carried out in a turbo decoder at the receiver end using soft-decision output signals. A return channel is provided, which the receiver uses to request the information from faulty packets once again. An RCPTC is used as the turbo code. When the information in a faulty packet is retransmitted, at least a portion of the information suppressed by the puncturing of the RCPTC in the previous transmission is transmitted. This additional information is inserted into the already existing information at the receiver end, and this completed information is decoded once again. When the repeat transmission is made, the only bits which are transmitted are those which are additionally available at the next lower coding rate, since they are not punctured.

Abstract: A remote terminal includes a receiver stage for receiving a transmitted signal and for delivering an analog signal. The remote terminal further includes an analog/digital converter for converting the analog signal to a digital signal, and a processing stage for processing the digital signal. The analog/digital converter is a delta-sigma converter having adjustable parameters, and the processing stage includes a tuning circuit for adjusting these parameters on the fly as a function of the transmission standard, of the actual rate of transmission of the useful data, and of the actual conditions of reception.

Abstract: A cellular telephone includes a plurality of power amplifiers having a common operating region. If one of the amplifiers has to be deselected, a desired moment for the switching to another amplifier is defined based upon a predetermined transmission interrupt criterion. The power continues to be adjusted with the currently selected amplifier until the instant of switch over. Switching to the other amplifier may then be performed after the transmission has been interrupted.

Abstract: A rake receiver uses a delayed version of the received sequence and a delayed version of a scrambling code. The flexible hardware structure of the time-aligning and descrambling unit includes at least two delay chains and one multiplier. By controlling two multiplexers, the delayed versions of the received sequence can be multiplied with an arbitrary scrambling code having an arbitrary phase. During one chip period, one multiplication is performed for each path to be processed.

Abstract: The electrical consumption of a cellular mobile telephone is reduced by using fractional-division phase-locked loops receiving a frequency reference from a fairly inaccurate quartz oscillator. Electrical consumption is also reduced by switching the output of the oscillator onto the input of the processing stage when the transmission/reception stage is inactive. The fractional-division phase-locked loops can then be deactivated.

Abstract: The new CDMA (Code Division Multiple Access) system structure which is equivalent to the structure of a CDMA system operating with direct code spread (DS, Direct Sequence) but operates with multicarrier (MC) methods. The multicarrier method is introduced a suitable selection of the spread code, with the result that the production of signals in CDMA systems with DS and with MC is harmonized and JD (Joint Detection) multisubscriber detection methods, which are known per se, with or without diversity reception can be used.

Abstract: In a method for data transmission on transmission channels in a digital transmission system, turbo coding is carried out in a turbo coder at a transmitter end for channel coding, and turbo decoding with soft-decision output signals is carried out in a turbo decoder at the receiver end. In order to improve the quality of service, the quality of service is determined from the variances of the soft-output signals at the turbo decoder, and the coding rate is set by adaptation of the puncturing such that a predetermined quality of service is obtained. Alternatively, the number of decoding iterations is set as a function of the quality of service. If a MAP symbol assessor is used at the receiver end, the variances &sgr;2LLR of the soft-decision output signals from the turbo decoder are determined, and the bit error rate is calculated from the variances &sgr;2LLR as a measure of the quality of service.