Abstract: Disclosed is a sub-Kelvin temperature zone refrigeration mechanism. The sub-Kelvin temperature zone refrigeration mechanism includes a pulse tube refrigeration unit, first pre-cooling heat exchangers, a throttling refrigeration unit, second pre-cooling heat exchangers, an adsorption refrigeration unit, a third pre-cooling heat exchanger and a dilution refrigeration unit. The pulse tube refrigeration unit includes a pulse tube refrigeration part. The throttling refrigeration unit includes a throttling refrigeration part, and the throttling refrigeration part is connected with the adsorption refrigeration unit through the second pre-cooling heat exchangers so as to pre-cool the adsorption refrigeration unit. The adsorption refrigeration unit includes an adsorption refrigeration part, and the adsorption refrigeration part is connected with the dilution refrigeration unit through the third pre-cooling heat exchanger.

Abstract: A flexible and scalable deployment of orthogonal frequency division multiplexing (OFDM) technology in a mobile cellular system, including a system that deploys multiple channels within a common base station, in which different modulation techniques are used to compensate for adjacent-channel interference.

Abstract: Several open-loop solutions encompass the small delay CDD codeword cycling and codeword cycling between different re-transmissions of both small and large delay CDD, and include an open-loop codeword cycling method for an SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.

Abstract: Several open-loop solutions encompass the small delay CDD codeword cycling and codeword cycling between different re-transmissions of both small and large delay CDD, and include an open-loop codeword cycling method for an SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.

Abstract: A base station capable of performing precoding in a wireless communication system is provided. The base station includes a plurality of codebooks and a codebook selector. Each codebook comprises a plurality of composite precoding matrices that are generated based on a corresponding diversity precoding matrix. The codebook selector is operable to select one of the codebooks for use in a communication session with a subscriber station.

Abstract: A system and method for minimizing a DC component of a received signal are disclosed. As one example, a system for minimizing a DC component of a signal in a wireless receiver is disclosed, which includes a programmable filter operable to filter the signal with at least one of a low cutoff frequency and a high cutoff frequency, and a transition unit coupled to the programmable filter, the transition unit operable to transition the programmable filter between the high cutoff frequency and the low cutoff frequency.

Abstract: In this invention, several open-loop solutions that encompass the small delay CDD codeword cycling, codeword cycling between different re-transmissions of both small and large delay CDD are proposed. In addition, an open-loop codeword cycling method for SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ, are proposed. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded by using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.

Abstract: A base station comprising an antenna array including M antennas for transmitting data to a plurality of subscriber stations. The base station generates a first pilot signal preamble by adding a first cyclic prefix to a first pilot signal sequence and generates a second pilot signal preamble by adding a second cyclic prefix to a second pilot signal sequence. The second pilot signal sequence is a circularly shifted copy of the first pilot signal sequence. The first pilot signal preamble is transmitted from a first antenna and the second pilot signal preamble is transmitted from a second antenna concurrently with transmission of the first preamble.

Abstract: A method of calibrating multiple types of base stations is provided. The method includes selecting one of a plurality of technology types for the wireless base station. The wireless base station has an adaptive antenna array. A calibration is performed for the wireless base station based on the selected technology type.

Abstract: A method for providing digital compensation and vector calibration for a base station in a wireless network is provided. The method includes performing a single process that is operable to provide simultaneously both digital compensation and vector calibration for the base station. According to one embodiment of the present disclosure, the single process is performed by receiving a transmitted signal based on a compensation/calibration (C/C) signal, processing the received signal, generating a C/C weight based on the processed signal, and using the C/C weight in a normal operational mode for the base station.

Abstract: In this invention, several open-loop solutions that encompass the small delay CDD codeword cycling, codeword cycling between different re-transmissions of both small and large delay CDD are proposed. In addition, an open-loop codeword cycling method for SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ, are proposed. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded by using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.

Abstract: A wireless terminal capable of communicating with a wireless communication system comprised of a plurality of wireless terminals and a plurality of base stations. The wireless terminal selects a sequence from a group of certain sequences for random access. At least one sub-carriers on an uplink channel including at least one data channel is allocated for at least one random access channel. Each data channel includes a continuous set of data sub-carriers. The wireless terminal then filters the at least one random access channel by applying a Raised Cosine filter, maps the selected sequence to the at least one random access channel to generate a random access channel signal, and transmits the random access channel signal to a base station.

Abstract: In this invention, several open-loop solutions that encompass the small delay CDD codeword cycling, codeword cycling between different re-transmissions of both small and large delay CDD are proposed. In addition, an open-loop codeword cycling method for SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ, are proposed. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded by using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.

Abstract: In a wireless network comprising a plurality of subscriber stations and a base station capable of providing service to the subscriber stations, a subscriber station is provided that includes a rank selector and a scheduling data reporter. The rank selector is operable to select a rank for the subscriber station. The rank is operable to identify a number of antennas for transmitting data streams from the base station to the subscriber station. The scheduling data reporter is operable to report scheduling data, including the rank, to the base station.

Abstract: A method and apparatus for channel sensing in a wireless communication device is provided. A self-signal intentionally transmitted to a first wireless device by another wireless communication device is detected in a signal received by the first wireless device. An original self-signal transmitted by the second wireless device is reconstructed from the detected self-signal. The reconstructed self-signal is then suppressed in the received signal and channel sensing is performed on the remaining signal. If the self-signal cannot be detected and verified in the received signal, the second wireless device may be requested to retransmit a modified self-signal and a predetermined number of attempts made to detect and verify the self-signal. Results of channel estimation performed on the received signal may be used in reconstructing the original self-signal. The channel estimation may include information from a plurality of frames in the received signal.

Abstract: A system, a receiver apparatus, a transmitter apparatus and a method for inter-user interference cancellation when simultaneous transmissions from two wireless users to the same base station are repeated using the same time-frequency resource. The percentage of interference cancellation is pre-set and phase shifts of the first and repeated transmitted symbols for each mobile user are determined in accordance with this pre-set percentage. The receiver uses a pre-determined technique for estimating the received symbols in accordance with the pre-set percentage and phase shifts.

Abstract: A system and method for channel estimation and echo cancellation in wireless system repeaters. A repeater with improved echo cancellation comprises an input radio control element having a receiving antenna and an output radio control element having a transmitting antenna; a power amplifier connected between the input radio control element and the output radio control element; and a signal processing unit connected between the input radio control element and the output radio control element. The signal processing unit is configured to estimate the communication channel from the transmitting antenna to the receiving antenna to produce a channel estimation. The signal processing unit is further configured to perform echo cancellation based on the channel estimation.

Abstract: A method for performing a soft handoff for a mobile station from a source base station to a target base station in an Orthogonal Frequency-Division Multiple Access (OFDMA) wireless network that is capable of communicating with a plurality of mobile stations in a coverage area of the OFDMA wireless network is provided. The method includes determining whether a relative delay between receipt of a source pilot signal from a source base station and receipt of a target pilot signal from a target base station is less than a downlink coherence time. When the relative delay is less than the downlink coherence time, the soft handoff is performed.

Abstract: A base station is disclosed for communicating with a subscriber station in a wireless network without requiring training signaling overhead. The base station is capable of combining a pilot signal with a data symbol and transmitting the combined pilot signal and data symbol to the subscriber station. A power level of the pilot signal is below a power level of the data symbol. The base station may be a single-input, single-output (SISO) antenna system or a multiple-input, multiple-output (MIMO) antenna system.

Abstract: A method of calibrating a base station that comprises an adaptive antenna array is provided. The method includes selecting one operational mode from a plurality of operational modes for the base station. An operational mode component set corresponding to the selected operational mode is selected from a plurality of operational mode component sets in the base station. The base station is calibrated using the selected operational mode component set.