5 results about "Spectral efficiency" patented technology

The invention discloses a method and device for controlling uplink power. The method comprises the steps of: calculating downlink path loss of a mobile station in a service cell; calculating path loss of the mobile station to an adjacent cell; calculating path compensating transmitting power of the mobile station according to the downlink path loss of the mobile station in the service cell and the path loss of the mobile station to the adjacent cell; and obtaining basic open loop transmitting power of the mobile station according to the path compensating transmitting power of the mobile station. According to the technical scheme provided by the invention, the system frequency spectrum efficiency and the cell edge user frequency spectrum efficiency can be simply and effectively combined.

The invention provides an uplink system of a subcarrier multiplexing optical network of filter based multicarrier modulation. The system comprises access control modules, filter based multicarrier modulation modules, subcarrier modulation modules, a multiplexing module, a feed line type fiber, a de-multiplexing module, photoelectric detectors, subcarrier demodulation modules and uplink data reception modules that are successively connected. Data generated by the access control modules is modulated in the filter based multicarrier modulation method, modulated user data is modulated to different optical subcarriers and transmitted via RF subcarrier modulation of optical carrier waves, and data from different units is multiplexed to uplink fiber channels. Filter based multicarrier modulation technology is combined with subcarrier multiplexing technology so that frequency spectrum resources of uplinks are utilized in high efficiency, interference among symbols and subcarriers of uplink users can be effectively resisted, and higher transmission speed and frequency spectrum frequency can be supported.

The invention discloses a method for coding a layered space-time code and a system thereof. The method comprises the following steps of: coding all the 2transmitting antennas of the transmitting end of a multiple input multiple output (MIMO) system; ensuring the number 2of the transmitting antennas of the transmitting end practical for transmitting a symbol, wherein, n is equal or greater than 0 and less than N; reading 2bit group with (N-n+m) length in a bit sequence which is to be transmitted, and coding the bit group; coding the bit group code and jointly forming into a binary sequence A with the (N-n) bit in the bit group, mapping the other m bit in the bit group into a symbol sj by M=2level modulation, and mapping the symbol sj to the transmitting antenna which is coded to be A; and judging whether the nt=2bit group has been mapped, if not, continuously executing the last step, otherwise, transmitting the symbol by 2 antennas which are mapped with the symbol by the transmitting end. Under the premise that spectrum effectiveness is invariable, the invention effectively improves the diversity order of the MIMO system so as to improve testing performance and reduce testing complexity.

Compared with a traditional FDD system measurement and control station, an uplink and downlink common-frequency aerospace ground measurement and control station disclosed by the invention has higher measurement and control spectrum efficiency and higher measurement precision. A first-stage interference suppression module is formed by four channels, and a second-stage interference suppression module formed by a sum channel, an azimuth difference channel and a pitch difference channel is arranged between a down-conversion module and a measurement and control baseband module; a time delay estimation module based on a spreading code is added in a second-stage interference suppression module so as to improve the synchronization precision between an interference reconstruction signal and a receiving signal; the antenna feed source adopts a transmitting and receiving feed source split antenna in which a transmitting feed source and a receiving feed source are separated, so that the isolation degree between transmitting and receiving signals is increased; a receiving and transmitting common-local-oscillator scheme is adopted, a unified local oscillator signal is distributed to the up-conversion module and the down-conversion module, it is guaranteed that reference signals and received self-interference have the same phase noise distribution, the self-interference cancellation efficiency is improved, and the technical difficulty of uplink and downlink common-frequency self-interference suppression is reduced.