摘要:
The specification and drawings present a new method, system, apparatus and software product for carrier frequency shifting in mobile communication systems, e.g., for eliminating or reducing interference, e.g., for a communication between a mobile station and a network element. The communication between the mobile station and the network element may be performed within a GSM/EDGE radio access network. A signal (e.g., a DSR or MDSR carrier) and at least one further signal (e.g., a speech carrier) are identified, wherein bandwidths of the signal and of the at least one further signal overlap. Then, a frequency shift for said signal may be determined according to a predetermined criterion and a carrier frequency of the signal may be shifted by the determined frequency shift, e.g., for eliminating or reducing the interference.
摘要:
A transmitter clips a transmission signal before transmission in order to reduce the strength of at least one peak of the transmission signal exceeding a predetermined threshold. The transmitter includes a clipper having a minimizer, a filter and an adder. The minimizer minimizes of a cost function with respect to an optimization signal, the cost function having weighted terms as a function of the optimization signal. The terms relate to an effective modulation distortion and an effective overshoot exceeding the predetermined threshold. The filter forms a clipping signal by filtering the optimization signal formed as a result of the minimization according to the spectrum emission mask requirements of the radio system. The adder subtracts the clipping signal from the transmission signal.
摘要:
A method for carrying out channel equalization in a radio receiver wherein an impulse response is estimated, noise power is determined by estimating a co-variance matrix of the noise contained in a received signal before prefiltering, and tap coefficients of prefilters and an equalizer are calculated. The method comprises determining the noise power after prefiltering by estimating a noise covariance matrix, after which input signals of the channel equalizer are weighted by weighting coefficients obtained from the noise covariance estimation.
摘要:
The invention relates to a method and arrangement for connecting a processor to an ASIC. In the arrangement, the processor generates control signals employed when the processor reads data from and writes data to the ASIC. The arrangement comprises means (10) for receiving control signals from the processor and generating read and write signals on the basis of the received signals. The means (10) are implemented by an asynchronous state machine that changes its state on the basis of the received signals. The means (10) change their state without a synchronizing clock signal.
摘要:
The invention relates to a reception method and a receiver. Mechanisms are used for generating, at each level, numbers relating to a bit 1 and a bit 2 and representing a probability of a transition metric of survivor paths. Mechanisms are used for separately summing the numbers relating to the bit 1 and the bit 0 of more than one state and representing the probability of the transition metric. Mechanisms are used for generating logarithms of the sums and means for generating a difference of the logic numbers relating to the bit 1 and the bit 0 representing the probability of the transition metric, whereby a received bit can be determined without a correct path tracing phase.
摘要:
The present invention relates to reception method and apparatus. The invention is characterized in that received symbols are function of bits which are determined by means of temporally successive trellis levels, which comprises a predetermined number of states, with a transition from each of the states to a state at the next level being performed on the basis of a received signal.
摘要:
The invention relates to a method for generating a signal amplitude behaving according to a desired function and to a converter implementing the method. In the method, a function that is used for controlling the behaviour of a signal amplitude is piecewise linearized to provide straight lines; a slope and a constant term of each straight line is stored in a memory (202 and 203); and a midpoint of each straight line is shifted to form an origin in a common coordinate system. Variable data (213) is used as address data, which is divided into an MSB (207) and an LSB part (208). The MSB part (207) is used for addressing from the memory (202 and 203) the slope and the constant term of the straight line. The LSB part (208) functions as a variable of a common coordinate system of the straight lines. The amplitude is generated by summing in a summer (205) a product determined by the slope and the LSB part to the constant term, the product being generated in means (204) as a selected summing of arithmetically shifted, masked and complemented slopes controlled by the LSB part.
摘要:
A base station for a mobile communication system which has switching centers and base stations connected by telecommunication links, each base station transmitting radio signals divided into a plurality of time-slots in a frame structure, a controller unit for controlling the base station; a transmitter for generating a transmission signal, the transmitter being connected to the switch to supply the transmission signal to the antenna via the switch; a counter for counting the length of time-slots in a frame structure synchronized by a frame alignment signal, a programmable memory in which one or more delay values are each stored as a counter value, a selecting unit for selecting a delay value desired by the user, and a power level memory responsive to the counter and storing power level memory momentary power values corresponding to the parts of the time-slots in the frame structure, as well as information on whether the switch supplying the transmission signal of the transmitter to the antenna is switched off or on, or neither, the power level memory being arranged so that each part of the time-slot in a frame structure is represented by a specific memory address of the power level memory, and in the memory location corresponding to the memory address, in addition to momentary power values of the curve indicating the power level, information is stored on whether the switch supplying the transmission signal of the transmitter to the antenna is switched off or on, or neither.
摘要:
A method and a receiver for forming transition metrics in the receiver of a digital cellular radio system. The receiver includes a hardware implementation of a transition metrics calculation unit for Viterbi decoding. The receiver includes a shift register for storing coefficients of a generator polynomial of a convolutional code. The receiver also includes masking means arranged to mask a state of the Viterbi decoding by the coefficients of the polynomial. The receiver has odd parity means arranged to form a parity bit of the state of the masked Viterbi decoding, the parity bit being arranged to control a block forming the transition metrics.
摘要:
A receiver and a method for determining connection quality in a cellular radio system. Received signals are decoded with a Viterbi decoder. Decision variables, representing decisions, are converted into a float value format. The converted decision variables are stored in a memory unit. During a traceback step of a Viterbi algorithm, a sum of absolute values of stored ones of the decision variables, which are in a correct path, are calculated and a minimum value of the absolute values of the stored ones of the decision variables in the correct path is calculated. The sum of the absolute values is averaged over a desired measurement period and compared to a predetermined threshold to obtain a bit error rate over a connection. Faulty signal frames are detected based on the minimum value of the absolute values.