The present application relates to a method of generating a downlink frame. The method of generating the downlink frame includes: generating a first short sequence and a second short sequence indicating cell group information; generating a first scrambling sequence and a second scrambling sequence determined by the primary synchronization signal; generating a third scrambling sequence determined by the first short sequence and a fourth scrambling sequence determined by the second short sequence; scrambling the short sequences with the respective scrambling sequences; and mapping the secondary synchronization signal that includes the first short sequence scrambled with the first scrambling sequence, the second short sequence scrambled with the second scrambling sequence and the third scrambling sequence, the second short sequence scrambled with the first scrambling sequence and the first short sequence scrambled by the second scrambling sequence and the fourth scrambling sequence to a frequency domain.

Detection of a confusion caused by scrambling code reuse is provided herein. Timing measurements, as observed by a mobile device, and an identification of primary scrambling codes associated with the timing measurements are captured. The timing measurements are identified by the primary scrambling codes for the particular radio measured. The mobile device also reports its location information. Radios for which timing measurements have been received are paired. Based on the paired radios and a history of observed time difference reference values for radio pairs, comparisons are made between paired radios having at least one common radio. Radios, exhibiting a set of values that is near an expected range, are removed from the analysis. Radios, exhibiting two sets of values that are distinct, are isolated in order to identify the radio that is causing the scrambling code confusion.

Apparatus and methods for symbol timing synchronization in a direct-sequence spread-spectrum receiver may use non-coherent integration, thresholding, peak selection, and curve fitting to determine appropriate timing instants at which to select despread samples for further processing, such as demodulation and decoding. The curve fitting may be used to search backwards and/or forwards in time to obtain the timing instants.

A method of performing cell search includes receiving a primary synchronization signal (PSS) comprising a primary synchronization code (PSC) and receiving a secondary synchronization signal (SSS) comprising a first secondary synchronization code (SSC) and a second SSC, wherein the SSS includes a first SSS and a second SSS, the first SSC and the second SSC are arranged in that order in the first SSS, and the second SSC and the first SSC are arranged in that order in the second SSS. Detection performance on synchronization signals can be improved, and cell search can be performed more reliably.

A satellite radio wave receiving processing unit 60 includes a front end 60a which receives a radio wave including a code signal transmitted from a satellite, and a baseband unit 64 which acquires the code signal from the received radio wave, in which the baseband unit identifies a pseudo-random code sequence used for performing spread spectrum to the code signal and a phase of the pseudo-random code sequence in a transmission period, identifies a code type of the code signal every time according to the transmission period, identifies, by comparing an array of the identified code type with a plurality of comparison arrays expected to appear as the array of the code type, a head timing of each code in the code signal according to a comparison array in which a result of the comparison satisfies a predetermined condition, and identifies each code in synchronization with the identified head timing.

Apparatus and methods for symbol timing synchronization in a direct-sequence spread-spectrum receiver may use non-coherent integration, thresholding, peak selection, and curve fitting to determine appropriate timing instants at which to select despread samples for further processing, such as demodulation and decoding. The curve fitting may be used to search backwards and/or forwards in time to obtain the timing instants.

A disclosure of the present specification provides a method for detecting a discovery signal. The method is a method for detecting discovery signals from a plurality of transmission points (TP) using the same physical cell identifier (PCID) and may comprise the steps of: determining scrambling identifiers of the discovery signals for the plurality of transmission points on the basis of the PCID which is commonly used by the plurality of transmission points and resource elements (REs) of the discovery signals transmitted from the plurality of transmission points; and demodulating the discovery signals on respective positions of the resource elements using the determined scrambling identifiers to detect the discovery signals.

Disclosed herein are methods and systems that involve an aiding signal that can be used to acquire a long code in a. wireless signal, such as a ranging code in a wireless navigation signal transmitted by a satellite. A receiver may receive a first wireless signal and a first aiding signal transmitted by a first transmitter of a plurality of transmitters. The first wireless signal comprises a first, long code. The first aiding signal comprises repeating instances of a sequence of short codes, wherein the sequence has a predetermined time relationship with the first long code and is specific to the first transmitter. The receiver may use the first aiding signal to acquire the first long code by determining the sequence of short codes in the first aiding signal and using the predetermined time relationship to synchronize with the first long code.

Techniques for processing a received multi-code code-division multiple-access (CDMA) signal to detect unused spreading codes are disclosed. An example method includes, for each of a plurality of observation time intervals and for each of one or more candidate spreading codes, determining a detection threshold for use in detecting whether the candidate spreading code is unused in the received multi-code CDMA signal, based on a target detection sensitivity and at least one of an estimate of received signal quality and an estimate of channel estimation quality. Estimated signal power for the candidate spreading code is compared to estimated noise and interference power corresponding to a spreading code that is known to be unused or corresponding to a spreading code that carries known symbol values, using the calculated detection threshold. Whether or not the candidate spreading code is unused is then determined, based on the comparison.

Apparatus and methods for symbol timing synchronization in a direct-sequence spread-spectrum receiver may use non-coherent integration, thresholding, peak selection, and curve fitting to determine appropriate timing instants at which to select despread samples for further processing, such as demodulation and decoding. The curve fitting may be used to search backwards and/or forwards in time to obtain the timing instants.