摘要:
A method of cancelling interference induced by a coherent interference source in a spread spectrum receive comprises the steps of: quantifying (44; 94) first interference values induced by the coherent interference source (SCH) in symbols on a first spread spectrum physical channel (P-CCPCH; CPICH); calculating (46, 48, 50; 96, 98, 100) second interference values induced by the coherent interference source in symbols on a second spread spectrum channel (DPCH) from the first interference values; and applying (18; 74) a correction value, derived from the second interference values, to the symbols on the second spread spectrum channel.
摘要:
A method of cancelling interference induced by a coherent interference source in a spread spectrum receiver comprising the steps of: quantifying (44; 94) first interference values induced by the coherent interference source (SCH) in symbols on a first spread spectrum physical channel (P-CCPCH; CPICH); calculating (46, 48, 50; 96, 98, 100) second interference values induced by the coherent interference source in symbols on a second spread spectrum channel (DPCH) from the first interference values; and applying (18; 74) a correction value, derived from the second interference values, to the symbols on the second spread spectrum channel.
摘要:
A method of cell search in a wireless communication systems having a plurality of base stations and a mobile station, each of the plurality of base stations serving a separate cell within a service area and transmitting a common primary synchronization code (PSC) in a primary synchronization channel within a slot of a radio frame, the method including the steps of: (a) scanning (72) through radio channels in scanning increments corresponding to a standard channel raster; (b) estimating (98) the PSC signal-to-noise ratio of each radio channel; (c) if a PSC signal-to-noise ratio is above a first predetermined threshold level (100), completing a cell search procedure including slot synchronization, frame synchronization and scrambling code detection steps for that radio channel; (d) if the cell search procedure is successfully completed (112) for the radio channel in step (c), increasing the scanning increments to the broadcast frequency separation between cells; (e) when all radio channels are scanned in step (d), sorting (74) the scanned radio channels in descending order by PSC signal-to-noise ratio; and (f) performing (76) the cell search procedure on each sorted radio channel in descending order.
摘要:
A method of cell search in a wireless communication systems having a plurality of base stations and a mobile station, each of the plurality of base stations serving a separate cell within a service area and transmitting a common primary synchronisation code (PSC) in a primary synchronisation channel within a slot of a radio frame, the method including the steps of: (a) scanning (72) through radio channels in scanning increments corresponding to a standard channel raster; (b) estimating (98) the PSC signal-to-noise ratio of each radio channel; (c) if a PSC signal-to-noise ratio is above a first predetermined threshold level (100), completing a cell search procedure including slot synchronisation, frame synchronisation and scrambling code detection steps for that radio channel; (d) if the cell search procedure is successfully completed (112) for the radio channel in step (c), increasing the scanning increments to the broadcast frequency separation between cells; (e) when all radio channels are scanned in step (d), sorting (74) the scanned radio channels in descending order by PSC signal-to-noise ratio; and (f) performing (76) the cell search procedure on each sorted radio channel in descending order.
摘要:
The carrier synchronization unit combines the recursive least square (RLS) type phase and amplitude estimation and the prediction in a decision-directed carrier synchronization strategy. The fading channel multiplicative distortion is estimated using an adaptive recursive least square method which minimizes a time-weighted square error. Combining prediction based on a least-square fading memory curve fit and extrapolation with RLS estimation the tracking delay effect is reduced. Resulting in an improvement of receiver performance. The proposed method minimizes the phenomenon of hang-up allowing rapid phase acquisition with high probability of success.
摘要:
A first EbIo estimator calculates EbIo using samples corresponding to data symbols and samples corresponding to pilot symbols. A diversity combined signal, which is obtained by coherent maximal ratio combining of paths signals is provided for the data symbol hard decisions. The data symbol hard decisions are used in EbIo measurement. The calculation for signal power uses re-modulation. The re-modulation is based on provided carrier signals. The carrier signal is derived using interpolated pilot symbols. The calculation for interference power uses a difference between a received signal and a re-modulated signal. A second EbIo estimator calculates EbIo using only samples corresponding to the pilot symbols. A rough error rate estimation uses the hard decisions for pilot samples and their comparison with known pilot symbols. If an estimated error rate is less than a predetermined threshold, the EbIo measured by first EbIo estimator is used for power control. When the estimated error rate is larger than the threshold, the EbIo measured by second EbIo estimator is used to control the power. The selection between the first and second EbIo estimator is for each slot EbIo measurement. The measured EbIo is compared with the preset EbIo threshold level, and as a result of this comparison, a command to lower or raise power is sent to the mobile station using the return channel.
摘要:
A carrier synchronizing unit for a coherent detection data communication system over non-frequency selective fading channels wherein the redundancy in estimation of a fading channel multiplicative distortion is reduced to improve the reliability of the estimation and compensate for an influence of a tracking delay in recursive least square estimation. The carrier synchronizing unit combines pilot symbols interpolation and recursive least square type phase and amplitude estimation. Carrier synchronizing unit comprises pilot symbol interpolation type phase and amplitude means for interpolating pilot symbols to estimate fading channel multiplicative distortion for the purpose of pre-detection, recursive least square type phase and amplitude estimation means to estimate fading channel multiplicative distortion in the second estimation stage, distortion compensation means to compensate fading distortion, symbol decision means for deciding a received data symbols using coherent detection, delay means for delaying a received signal, and means for periodically training of the recursive least square type phase and amplitude means. The fading channel multiplicative distortion is estimated in the second stage using a recursive least square method which minimizes a time-weighted square error.