A personal navigation device includes a correlator for processing GNSS signals from a constellation of satellites A signal is received from a navigation beacon containing a repeating code word, in which the code word includes a number N of samples corresponding to N phases, and in which reception of each code word occurs within a defined time period T. The sequence of N code samples is correlated with a known code word to determine a maximum value of correlation for a particular phase of the received signal. The correlation is performed using a correlator of size M, in which M is less than N, such that N/M=P complete correlations for a partial code phase are performed such that each correlation of a partial code phase is performed within a time period of approximately T/P. All P correlations of partial code phases are completed within time T.

Embodiments provide a receiver having a receiving unit and a synchronization unit. The receiving unit is configured to receive a data packet having a pilot sequence. The synchronization unit is configured to separately correlate the pilot sequence with at least two partial reference sequences corresponding to a reference sequence for the pilot sequence of the data packet, in order to obtain a partial correlation result for each of the at least two partial reference sequences, wherein the synchronization unit is configured to non-coherently add the partial correlation results in order to obtain a coarse correlation result for the data packet.

Embodiments provide a receiver having a receiving unit and a synchronization unit. The receiving unit is configured to receive a data packet having a pilot sequence. The synchronization unit is configured to separately correlate the pilot sequence with at least two partial reference sequences corresponding to a reference sequence for the pilot sequence of the data packet, in order to obtain a partial correlation result for each of the at least two partial reference sequences, wherein the synchronization unit is configured to non-coherently add the partial correlation results in order to obtain a coarse correlation result for the data packet.

A personal navigation device includes a correlator for processing GNSS signals from a constellation of satellites A signal is received from a navigation beacon containing a repeating code word, in which the code word includes a number N of samples corresponding to N phases, and in which reception of each code word occurs within a defined time period T. The sequence of N code samples is correlated with a known code word to determine a maximum value of correlation for a particular phase of the received signal. The correlation is performed using a correlator of size M, in which M is less than N, such that N/M=P complete correlations for a partial code phase are performed such that each correlation of a partial code phase is performed within a time period of approximately T/P. All P correlations of partial code phases are completed within time T.

A receiver is provided for acquiring a DSSS signal. The receiver includes a splitter, a first multiplier, a second multiplier and a processor. The splitter is operable to split the DSSS signal into a first DSSS signal and a second DSSS signal. The first multiplier is operable to multiply the first DSSS signal by a shuffled pseudo-noise sequence and a sine function to obtain a first correlation value. The second multiplier is operable to multiply the second DSSS signal by the shuffled pseudo-noise sequence and a cosine function to obtain a second correlation value. The processor is operable to determine an alignment delay based on the first correlation value and the second correlation value.

A digital radio receiver (7) is arranged to receive and process data frames, each data frame comprising (i) a plurality of identical synchronization sequences; (ii) identification data different from the synchronization sequences; and (iii) convolution-encoded message data. An initial-synchronization section of the receiver (7) uses the plurality of synchronization sequences in a received data frame to perform a frequency-synchronization or symbol-timing-synchronization operation. A frame-synchronization section determines frame-synchronization information by correlating at least a part of the received identification data against reference identification data stored in a memory. A convolution-decoding section uses the frame-synchronization information to decode the message data.

Embodiments provide a receiver having a receiving unit and a synchronization unit. The receiving unit is configured to receive a data packet having a pilot sequence. The synchronization unit is configured to separately correlate the pilot sequence with at least two partial reference sequences corresponding to a reference sequence for the pilot sequence of the data packet, in order to obtain a partial correlation result for each of the at least two partial reference sequences, wherein the synchronization unit is configured to non-coherently add the partial correlation results in order to obtain a coarse correlation result for the data packet.

A GNSS correlator comprises a buffer and a processing unit. The buffer is configured to store input data representing sample values of a GNSS signal captured over a pre-defined time window. The processing unit is configured to receive one or more correlation parameters in a control signal, and, in a first pass, read the input data from the buffer and perform a first correlation operation on the input data, and, in a second pass, re-read the same input data from the buffer and perform a second correlation operation on the same input data, wherein the second correlation operation is different to the first correlation operation.

Embodiments provide a receiver having a receiving unit and a synchronization unit. The receiving unit is configured to receive a data packet having a pilot sequence. The synchronization unit is configured to separately correlate the pilot sequence with at least two partial reference sequences corresponding to a reference sequence for the pilot sequence of the data packet, in order to obtain a partial correlation result for each of the at least two partial reference sequences, wherein the synchronization unit is configured to non-coherently add the partial correlation results in order to obtain a coarse correlation result for the data packet.

Embodiments provide a receiver having a receiving unit and a synchronization unit. The receiving unit is configured to receive a data packet having a pilot sequence. The synchronization unit is configured to separately correlate the pilot sequence with at least two partial reference sequences corresponding to a reference sequence for the pilot sequence of the data packet, in order to obtain a partial correlation result for each of the at least two partial reference sequences, wherein the synchronization unit is configured to non-coherently add the partial correlation results in order to obtain a coarse correlation result for the data packet.