Abstract: The present invention generally relates to the field of wireless communication systems. It particularly refers to a spatial diversity transmitter (110) and a spatial diversity receiver (120) in a wireless multiple-input multiple-output (MIMO) spatial multiplexing system as well as a corresponding method for wirelessly transmitting and receiving modulated RF signals via multiple wireless signal propagation paths (Pl) of a multipath fading channel in a way that correlation between the MEMO channel components are reduced and/or the signal to interference plus noise ratio (SINR) is increased which hence result in an improved bit error rate (BER) or packet error rate (PER) performance of said wireless MIMO spatial multiplexing system. On the receiver side, for example, this is achieved by controlling at least one antenna switching and/or combining means (121a?+b?) to select a specific combination of different fixed beam antennas (121a+b) from each receiver-resident antenna array.

Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively.

Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna mean, respectively.

Abstract: The present invention relates to a communication device (1) for transmitting and receiving data in a communication system and a corresponding communication method. In the communication system, which can be a wireless or a wired communication system, a random access channel is provided, which comprises a plurality of access resources. The access resources are divided in at least two access resource groups, each access resource groups corresponding to a different access service class with a respective access probability.

Abstract: A transmitting device for transmitting data symbols and pilot symbols in an OFDM transmission system; the device comprising symbol generating means for generating said data symbols and said pilot symbols, means for transmitting said data symbols and pilot symbols respectively by using a plurality of subcarriers of said OFDM transmission system, wherein said symbol generating means is designed to selectively generate a first type pilot symbol and a second type pilot symbol being orthogonal to said first type pilot symbol so that a pilot symbol pattern in the frequency dimension comprises at least said first type pilot symbol to be transmitted by using a predefined subcarrier and second type pilot symbol to be transmitted by using other predefined subcarrier, and wherein said pilot symbol pattern has a different pattern from a succeeding pilot symbol pattern in time dimension.

Abstract: The present invention relates to a transmitting device and a receiving device in a wireless orthogonal frequency division multiplex (OFDM) communication system with space time transmit diversity (STTD). Further, the present invention relates to a channel estimation method for performing a channel estimation in such a wireless communication system, in which the transmitting device comprises a first and a second antenna for transmitting signals with space time transmit diversity. The first and the second antenna means are arranged spaced apart from each other in a space diversity arrangement, whereby first and second pilot symbols are transmitted via said first and said second antenna means, respectively.

Abstract: The present invention relates to a device (10) for receiving signals in a wireless orthogonal frequency division multiplex (OFDM) system and to a channel estimation method in such a system. The data symbols and pilot symbols are transmitted in frequency subcarriers and timeslots, whereby pilot symbols are transmitted in a continuous stream within at least one frequency subcarrier. A channel estimation for a data symbol is performed on the basis of received pilot symbols using a filter including a common phase error correction value from the continuous stream pilot symbol in the same timeslot as the data symbol to be channel estimated. The present invention thereby enables a correct and efficient channel estimation including a common phase error correction to be performed.

Abstract: The invention proposes a device for generating, from incoming signal values (Xi,n), soft-values (Yi,n) to be input into a channel decoder of a communication device for use in a wireless communication system, comprising truncation means (24, 26, 28) for truncating the incoming signal values (Xi,n) such as to fall within a predetermined limit value range, and normalization means (30, 32) for normalizing the truncated signal values (Xti,n) such as to fit to an input range of the decoder. According to the invention, the truncation means (24, 26, 28) are adapted to determine the boundaries of the limit value range in dependence on information representative of a signal-to-noise ratio of the incoming signal values (Xi,n). The truncated signal values (Xti,n), after normalization, then are output as said soft-values (Yi,n).

Abstract: The present invention relates to an equalising structure and method for a receiving device of a wireless communication system, in which transmit information is modulated onto carrier signals according to a modulation scheme, whereby all possible data symbols are represented as constellation points in the signal constellation of the modulation scheme and whereby the equalizing structure performs a maximum likelihood detection in order to determine a constellation point with a minimum Euclidean distance to a received signal vector as a most likely received signal vector, with dividing means for dividing the constellation points into two or more groups of constellation points, allocating means for allocating a representative signal vector to each of the formed groups, first detecting means for performing a maximum likelihood detection in order to determine one or more of the representative signal vectors having the minimum Euclidean distance to the received signal vector, and second detecting means for performin

Abstract: A frame synchronisation is proposed for a multi-band communication system, wherein a data signal exchanged between a transmitter and a receiver is organised in system frames having a preamble section which contains a frame synchronisation section that is composed of a number of symbol frames, each of which is in turn composed of a defined number of slots, whereby each slot corresponds to an individual transmission frequency band. The method comprises steps for transmitting the data signal containing a synchronisation signal in one or more slots of every other symbol frame of the frame synchronisation section, processing only data signal components selected from transmission frequency bands required for the synchronisation signal transmission, and subtracting the processed data signal from its shifted copy, whereby the copy is shifted by one symbol frame.

Abstract: A frequency modulation method is proposed that enables an imprinting of a digital message formed by a sequence of symbols on a set of frequency bands. Each symbol of the digital message is hereby assigned just one symbol value out of a defined set of symbol values. According to the method at least two symbol transmission channels are defined with each symbol transmission channel being formed by a sub-set of frequency bands selected from the set of frequency bands and with each frequency band of a symbol transmission channel being allocated to a symbol value of the set of symbol values in a one-to-one relation such, that the symbol transmission channels defined differ from each other in at least one frequency band selected and/or in an allocation of a frequency band to a symbol value. Further, each of the defined symbol transmission channels is successively modulated with a single symbol value of the digital message according to the channel allocation scheme of the respective symbol transmission channel.

Abstract: A communication system is proposed which implements a method for up-converting a baseband signal to a given number of frequency bands that together define a signal transmission channel, whereby the method comprises a step for defining a sequential order in which the frequency bands are to be used for up-converting the baseband signal, and a step for up-converting the baseband signal to one frequency band after the other in the defined sequential order such that the spectral distance between two frequency bands is equal or higher for the frequency bands being direct neighbours in the defined sequential order than being direct neighbours in the spectral order.

Abstract: The present invention relates to a cellular communication system for wireless telecommunication on the basis of an OFDM scheme, comprising a plurality of base stations B, whereby at least one base station B is allocated to each cell C of the communication system and whereby information communicated from the base stations comprises data parts and pilot parts. The present invention further relates to a method for operating such a cellular communication system. The present invention is characterised in that the frequency reuse factor of the data parts is different from a frequency reuse factor of the pilot parts. Hereby, an optimisation between high capacity and reliable and correct channel estimation on the basis of the pilot parts can be achieved.

Abstract: To provide a higher data rate service on one link, it is possible to use more than one scrambling code per link. In this way, the same channelization code can be reused and a higher data rate can be supported because the highest data rate is restricted by the set of channelization codes with the shortest length. When reusing one and the same channelization code for spreading the two different data streams transmitted in one link and scrambling these two data streams by two different scrambling codes, the complexity of the receiver will be reduced. Therefore, the two data streams are spread with one and the same channelization code. After this, each of these data streams is scrambled with a different scrambling code.

Abstract: A time slot which is formed by time-division multiplexing is divided into a plurality of blocks in at least a frequency direction, and also within each one of said plurality of blocks a plurality of subcarriers are formed. A predetermined number of plurality of blocks forms one communication channel, whereby a plurality of communications are formed within a time slot. With this, one time slot can be multiplexed by communication of multiple carriers separated in frequency. In this manner, with simple constitution, communication can be performed satisfactorily even in an environment where a multiple path is present.

Abstract: The invention relates to an improved channel estimation technique for coherent CDMA systems. Traditionally channel estimators for coherent CDMA systems are based on a correlator. However, channel estimators based on this traditional approach are subject to the effect interpath interference, which caused performance to be degraded. The CDMA channel estimation technique eliminates the effects of interpath interference by using a cancellation technique. Therefore, estimate values output from a path searcher (30) respectively passed through a scaling unit (31) and a cross correlation calculator (32). The cross correlation term can be easily calculated since the path delay and the spreading sequence are known at the receiving side. The output signals of the cross correlation calculator (32) are respectively subtracted from the original estimation value {circumflex over (&agr;)}0 in a subtracting unit (33) to generate an improved estimation value to be supplied to an input terminal (27) of a RAKE combiner (26).

Abstract: The present invention proposes communication devices (1, 6) and a method for transmitting and receiving random access bursts in a random access channel of a digital telecommunication system. Thereby, a random access burst comprising a preamble part for acquiring a part of said random access channel and at least one message part for transmitting data in said acquired part of the random access channel is generated, whereby the number of message parts depends on an amount of data to be transmitted in the message parts. In case that two or more message parts are generated, each preceding message part comprises a continuation indicator indicating a succeeding message part. After transmission of such a random access burst, the continuation indicator is detected and a further part of the random access channel is reserved for the succeeding message part.

Abstract: According to the present invention a transmitter and a transmitting method for communicating data symbols over a communication channel, for example, according to the CDMA system is presented. The transmitter (24, 25) comprises means (9) for spreading each data symbol with a respective spreading code, wherein the spreading codes are mutually orthogonal. Means (10) for scrambling are provided to scramble each spread symbol with a respective scrambling code, the scrambling codes respectively having the same length as the spreading codes. Furthermore, means (11) for the transmission of the spread and scrambled symbols are provided. According to the present invention the means (10) for scrambling are provided with a plurality of different scrambling codes, which can be used simultaneously within the same link.

Abstract: The present invention relates to a cellular communication system for wireless telecommunication on the basis of an OFDM scheme, comprising a plurality of base stations B, whereby at least one base station B is allocated to each cell C of the communication system and whereby information communicated from said base stations comprises data parts and pilot parts. The present invention further relates to a method for operating such a cellular communication system. The present invention is characterised in that the frequency reuse factor of the data parts is different from a frequency reuse factor of the pilot parts. Hereby, an optimisation between high capacity and reliable and correct channel estimation on the basis of the pilot parts can be achieved.

Abstract: The present invention relates to a device (10) for receiving signals in a wireless orthogonal frequency division multiplex (OFDM) system and to a channel estimation method in such a system. The data symbols and pilot symbols are transmitted in frequency subcarriers and timeslots, whereby pilot symbols are transmitted in a continuous stream within at least one frequency subcarrier. A channel estimation for a data symbol is performed on the basis of received pilot symbols using a filter including a common phase error correction value from the continuous stream pilot symbol in the same timeslot as the data symbol to be channel estimated.