Methods, systems, and devices for satellite operations are described. A satellite communications system may include a transmitter that applies multiple spreading codes to a data signal to obtain multiple spread data signals. The transmitter may transmit the multiple spread data signals from multiple antenna elements in a composite signal. The satellite communications system may also include a receiver that receives the composite signal and applies multiple despreading codes to the composite signal to obtain multiple despread data signals. The receiver may combine the multiple despread data signals to obtain a combined data signal that corresponds to the data signal processed by the transmitter. To combine the multiple despread data signals, the receiver may estimate coefficients for each of the despread data signals.

The present disclosure provides an information transmission method, including: generating first information; determining a first sequence from N candidate sequences based on the first information; and sending the first sequence. The first information belongs to N candidate information. A mapping between the first information and the first sequence belongs to P mappings. Each of the P mappings includes a mapping between the N candidate information and the N candidate sequences. The N candidate sequences are generated based on N dedicated cyclic shift values and a first initial cyclic shift value. In at least two mappings, dedicated cyclic shift values used to generate candidate sequences corresponding to a same candidate information are different, where the same candidate information belongs to L candidate information in the N candidate information, both P and L are integers greater than 1, and the L is less than or equal to N.

A quadrature amplitude modulation (QAM) transmitter separates an input digital level into I and Q components. In a variation, a QAM transmitter uses every other input digital level as an I or Q component. A QAM receiver receives a QAM modulated signal and outputs digital levels. A QAM transmitter for transmitting analog levels uses a pair of input analog levels as the I and Q components. A QAM receiver receives a QAM modulated signal and outputs analog levels. The digital and analog input levels are produced by encoding N samples using L orthogonal codes.

A user equipment (UE) may be configured to receive a signal in a time slot, wherein the signal includes a first reference signal, a second reference signal and data scrambled using a data scrambling sequence. Further, the first reference signal and the second reference signal are not scrambled using the data scrambling sequence. The second reference signal having a code sequence being a non-zero power of two in length and is time multiplexed with the data. The UE recovers the data of the received signal using the first or second reference signal.

Digital or analog samples are sent from a video source to a video storage subsystem that encodes the samples into analog levels, stores the analog levels for a period of time, decodes the analog levels back into digital samples and then sends the digital samples to a video sink for display, N samples are encoded into L analog levels for storage. The storage subsystem may be located at the video source, at the video sink, or anywhere in between the two. The storage subsystem may be located on an electromagnetic pathway over which the L encoded analog levels are transmitted from a video source as an analog signal. The L encoded analog levels are written to storage and then later read from storage and retransmitted over the electromagnetic pathway toward a video sink. The storage subsystem may also be integrated with a transmitter that encodes the samples into analog levels for storage or may be integrated with a receiver that stores the analog levels and then decodes the analog levels back into samples. A sentinel track in the storage array detects attenuation or offset which is then compensated for.

Aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for control signal transmission. One aspect provides a method for wireless communication by a user equipment (UE). The method generally includes receiving, from a base station (BS), a message indicating multiple configurations for physical uplink control channel (PUCCH) transmission; selecting, from a sequence database, a sequence to be used for the transmission of a PUCCH in accordance with one of the multiple configurations indicated by the message from the base station; and transmitting the PUCCH using the selected sequence.

User equipment (UE) applies a first code division multiplex access (CDMA) code to a baseband signal to generate a first signal, and a second CDMA code to the baseband signal to generate a second signal. The UE then transmits the first signal to a receiving device via a first antenna, and the second signal to the receiving device via a second antenna. The receiving device receives the first and second signals as a combined signal at an antenna, and extracts the first signal from the combined signal using the first CDMA code, and extracts the second signal from the combined signal using the second CDMA code. The CDMA codes may be real-valued or complex-valued. In some embodiments, the UE may separate the baseband signals into first and second portions, and transmit the first portion as part of the first signal and the second portion as part of the second signal.

A wireless device is configured to produce a signal in a time slot, the signal having a first portion and a second portion. Wherein, the first portion being a first in time in the time slot and the second portion being last in time in the time slot. Further, the first portion having data and a multiplexed first pilot and the second portion having a pilot sequence and a cyclic prefix. The wireless device transmits the produced signal in the time slot.

To solve a problem that unless all of a plurality of AICH signature states are correctly decoded, the contents of reception results cannot be recognized and the error rate of signature decoding will be high. In this embodiment, a base station uses, out of a signature combination, the signature of at least one predetermined position to indicate information containing a preamble reception result and uses the signature of a position other than the predetermined position to indicate a transmission profile information number of an uplink channel for notification to a user equipment. Thus, the error rate related to reception results can be reduced as compared with the case where a single signature combination is used to notify all pieces of information.

The disclosed techniques allow for transmitting a signal stream from a sender to a receiver in an environment including multiple senders and receivers. The technique for the sender decomposes a data stream from the sender into multiple substreams, encodes a substream by a codeword, further superimposes multiple codewords to form a signal stream in an asynchronous manner, and transmits the signal stream to the receiver. A codeword can span over multiple blocks. The receiver receives a first codeword stream from a first sender, receives a second codeword stream from a second sender, the two codeword streams may be received at the same time as one signal, and decodes the first codeword stream and second codeword stream over a sliding window of multiple blocks.