Infineon Technologies Ag

Siemens Aktiengesellschaft

J&ouml;rg Plechinger

Peter Jung

Markus Doetsch

Peter Schmidt

Michael Schneider

Friedbert Berens

Tideya Kella

Markus D&ouml;tsch

Burkhard Becker

Karl Kammerlander

Paul-Walter Baier

S&ouml;nke Mehrgardt

Sven Simon

A method is described for estimating channel impulse responses of a mobile radio channel with a broad bandwidth by a code division multiplexing method, and with a synchronization channel continuously transmitting sequences to mobile radio receivers. The sequences are provided for synchronization of each mobile radio receiver and are known to each of the mobile radio receivers. The transmitted sequences have pilot symbols for identifying the synchronization channel, and the pilot symbols are transmitted at points that are known to the receivers within a time slot. When searching for and identifying the synchronization channel, the pilot symbols and, possibly, further symbols and sequences which are known in the receivers, are evaluated to estimate the delay times and the complex amplitudes, of the mobile radio channel responses.

Method for estimating channel impulse responses of a mobile radio channel

A circuit configuration has a radio-frequency section with a receiving mixing stage, and has a signal processing circuit with an A/D converter, a digital filter and a frequency estimator. The frequency estimator continuously determines a first frequency correction control signal, which is representative of a frequency offset between the frequency of an IF received signal and a frequency which is characteristic of a pass band of the filter. The first frequency correction control signal is used for readjustment of the mixing frequency.

Frequency-stabilized transmitting/receiving configuration

A method for estimating a channel impulse response of a mobile radio channel is described. The mobile radio channel is accessed over a wide bandwidth by a code division multiplex method. A second mobile radio channel continuously transmits sequences to a multiplicity of mobile radio receivers, and the sequences are known to each of the multiplicity of mobile radio receivers. The delay parameters of the mobile radio channel are estimated using the sequences transmitted via the second mobile radio channel. The mobile radio receiver is adjusted in accordance with the delay parameters estimated and weighting factors of the mobile radio channel are determined.

Method for estimating the channel impulse response of a mobile radio channel

A circuit configuration for a multistandard communications terminal has, for the reception of radio signals, a radio frequency component with a receive conversion stage and a signal-processing circuit connected downstream of the radio frequency component. The signal-processing circuit has an A/D converter and a digital filter. The pass-band of the digital filter is variable. In operation, the pass-band is set according to a selected system standard of the received radio signals.

Circuit configuration for a multistandard communications terminal

A device for carrying out search procedures includes a memory for storing a digital received data sequence, and a memory storing a predetermined correlation data sequence. A correlation device has a first section, in which sequence elements of the received data sequence are correlated with sequence elements of the correlation data sequence. A variable number K of sequence element correlation results are summed in the second section, in order to form an accumulated correlation result.

Device and system for carrying out search procedures in a mobile radio receiver

Transmission data that will be transmitted is coded and thus band-spread using a spread code. The band-spread transmission data is also coded using a scrambling code. The scrambling process is followed by pulse shaping, frequency correction, and DC offset and/or amplitude compensation for the band-spread and scrambled transmission data.

Method and apparatus for producing spread-coded signals

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; of the log-likelihood ratio LLR of the soft-decision output signals from the turbo decoder. The variances &sgr; 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.

Method and device for assessing the quality of service on transmission channels in a digital transmission system

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 &lsqb;. . .&rsqb; inserted into the already existing information at the receiver side, and this complete information is decoded again.

Method for transmitting data in a digital transmission system given a packet-switched service

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. The method is repeated, until the packet is decoded without any errors or all of the coded information in a packet is transmitted.

Method for packet transmission with an ARQ protocol on transmission channels in a digital transmission system

Convolutional codes are decoded by calculating, for uncoded and coded symbols, a first and/or second item of reliability information (&Lgr; and &Lgr; respectively). The item of reliability information is representative of the probability that the considered n uncoded or coded symbol is equal to a value i of the symbol set, under the condition that a specific sequence of received coded symbols is present. An approximate expression is proposed for calculating the second item of reliability information.

Method and device for decoding convolutional codes

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.

Growing community of inventors

München, Germany

Jörg Plechinger

Growing community of inventors

München, Germany

J&ouml;rg Plechinger

Jörg Plechinger