Abstract: Code synchronization is acquired as a part of receiving and decoding a spread spectrum transmission. There are received a number of signal samples that constitute a signal sample sequence. It represents a length of a received signal spread with one full length of a pseudorandom sequence used as a spreading code. The signal sample sequence is augmented at least at one end with at least one additional symbol, which produces a padded signal sample sequence. The padded signal sample sequence is in turn correlated with a locally produced sample sequence that comprises code samples representing a known form of said spreading code. The result of said correlating is used as a basis for acquired code synchronization.

Abstract: The invention relates to a method for determining the position xp of a peak of a pulse in a signal received at a receiver. In order to improve the accuracy of this determination, the method comprises taking samples of said received signal, determining at least three samples, at least one of which has a signal strength exceeding a threshold value, and determining the position xp of the pulse peak based on an interpolation of at least two of the determined samples, which at least two samples are selected based on the signal strengths of the at least three determined samples, and which interpolation includes an evaluation of the signal strength of the at least two samples. The invention relates equally to a device and to a cellular communication system comprising means for realizing this method.

Abstract: An apparatus including a spreading code generator for generating a spreading code; a scrambling code generator for generating a scrambling code; and a modulator for scrambling the spreading code using the scrambling code to produce a modified spreading code.

Abstract: A method for determining a delay of a spread data symbol stream comprises the steps of at least partially correlating a signal, which comprises at least first and second spread data symbol streams (300, 301) that are obtained by spreading at least a first and second data symbol stream with a respective first (302) and second code, with said first code (302) to obtain at least two portions (303-1, 303-2) of a Cross-Correlation Function CCF (303), and combining said at least two portions (303-1, 303-2) of said CCF (303) to obtain a combined CCF portion from which a first delay of said first spread data symbol stream is determined, wherein said first code (302) and said second code are composed of chips and wherein the number of chips of said first code (302) is different from the number of chips of said second code. The invention further relates to a computer program, a computer program product, a device and a system.

Abstract: The invention relates to a method for estimating a delay of a signal received at a mobile station MS from a specific network element BS1, BS2 of a network for determining the location of the mobile station. In order to reduce the false alarm ratio and to increase the acquisition probability, it is proposed that the method comprises estimating the delay within a search window. The search window is determined based on location information available for the specific network element BS1, BS2 and on a known distance of the mobile station MS to at least one other network element BS0, BS1. The invention relates equally to a corresponding mobile station MS, to a corresponding network element BS0, and to a communication system comprising at least one mobile station and at least two network elements.

Abstract: Code synchronization is acquired as a part of receiving and decoding a spread spectrum transmission. There are received a number of signal samples that constitute a signal sample sequence. It represents a length of a received signal spread with one full length of a pseudorandom sequence used as a spreading code. The signal sample sequence is augmented at least at one end with at least one additional symbol, which produces a padded signal sample sequence. The padded signal sample sequence is in turn correlated with a locally produced sample sequence that comprises code samples representing a known form of said spreading code. The result of said correlating is used as a basis for acquired code synchronization.

Abstract: A method of channel estimation in a cellular communication system is described. Symbols are transmitted between a mobile station and a base station. According to the described method, an incoming signal is received via a communication channel. A first estimate for the channel impulse response of that communication channel is provided and used to process the incoming signal to generate an estimated data symbol. The estimated data symbol is used to generate a soft output feedback decision which is then used to make a further estimate of the channel impulse response.

Abstract: A method for determining a delay of a spread data symbol stream comprises the steps of at least partially correlating a signal, which comprises at least first and second spread data symbol streams (300, 301) that are obtained by spreading at least a first and second data symbol stream with a respective first (302) and second code, with said first code (302) to obtain at least two portions (303-1, 303-2) of a Cross-Correlation Function CCF (303), and combining said at least two portions (303-1, 303-2) of said CCF (303) to obtain a combined CCF portion from which a first delay of said first spread data symbol stream is determined, wherein said first code (302) and said second code are composed of chips and wherein the number of chips of said first code (302) is different from the number of chips of said second code. The invention further relates to a computer program, a computer program product, a device and a system.

Abstract: The invention relates to a method for estimating a delay of a signal received at a mobile station MS from a specific network element BS1, BS2 of a network for determining the location of the mobile station. In order to reduce the false alarm ratio and to increase the acquisition probability, it is proposed that the method comprises estimating the delay within a search window. The search window is determined based on location information available for the specific network element BS1, BS2 and on a known distance of the mobile station MS to at least one other network element BS0, BS1. The invention relates equally to a corresponding mobile station MS, to a corresponding network element BS0, and to a communication system comprising at least one mobile station and at least two network elements.

Abstract: The invention relates to a method for determining the position xp of a peak of a pulse in a signal received at a receiver. In order to improve the accuracy of this determination, the method comprises taking samples of said received signal, determining at least three samples, at least one of which has a signal strength exceeding a threshold value, and determining the position xp of the pulse peak based on an interpolation of at least two of the determined samples, which at least two samples are selected based on the signal strengths of the at least three determined samples, and which interpolation includes an evaluation of the signal strength of the at least two samples. The invention relates equally to a device and to a cellular communication system comprising means for realizing this method.

Abstract: In a mobile communication system, a method and circuit for symbol estimation is described. According to the method, a soft output decision for a symbol is estimated and is fed back to modify decisions made for a subsequent set of received samples. This has the advantage of conveying not only information about the most likely symbol, but also information about the noise environment.

Abstract: The invention relates to a method of reducing interference in a radio system comprising at least one base station and a subscriber terminal. The data to be transmitted is converted into symbols in a transmitter and each symbol is multiplied by a connection-specific spreading code composed of chips. The data to be transmitted on connections in a synchronizing phase is multiplied by a spreading code whose duration in time differs from the spreading code in the other connections.

Abstract: A method of channel estimation in a cellular communication system is described. Symbols are transmitted between a mobile station and a base station. According to the described method, an incoming signal is received via a communication channel. A first estimate for the channel impulse response of that communication channel is provided and used to process the incoming signal to generate an estimated data symbol. The estimated data symbol is used to generate a soft output feedback decision which is then used to make a further estimate of the channel impulse response.

Abstract: In a mobile communication system, a method and circuit for symbol estimation is described. According to the method, a soft output decision for a symbol is estimated and is fed back to modify decisions made for a subsequent set of received samples. This has the advantage of conveying not only information about the most likely symbol, but also information about the noise environment.

Abstract: A method of measuring the frequency difference between a tuning frequency and a transmission frequency is provided. The method includes generating temporally successive estimated impulse responses and comparing the mutual temporal shift of the impulse responses in relation to one another. Additionally, the method includes generating a phase shift between the impulse responses corresponding to the comparison and forming a frequency difference between the transmission frequency and the tuning frequency corresponding to the phase shift. As the estimated impulse responses are generated in succession at given intervals and as the signal is being sampled at a given sampling frequency, the phase shift is generated corresponding to the highest correlation value. The frequency difference between the transmission frequency and the tuning frequency is formed as the ratio of the product of the phase shift and the tuning frequency to the product of the measurement interval and the sampling frequency.

Abstract: A receiver, and a data transmission method in a system wherein the CDMA multiple access method in a system wherein the CDMA multiple access method is utilized and wherein each data signal to be transmitted is multiplied by a pseudorandom code of a certain length, having a bit rate that is higher than that of the data signal to be transmitted. In order to ensure fast and inexpensive reception, the signal multiplied by the pseudorandom code is further modulated by a group of waveforms (f.sub.1 . . . f.sub.N) the number of which equals the number of bits in the pseudorandom code, the frequency domain given. The signal is converted in the receiver into a digital form and multiplied by the pseudorandom code which has been subjected to an inverse Fourier transform, and the multiplied signal is subjected to a Fourier transform.