Chain circuit self-adaptive method based on signal-noise ratio in high-speed downstream grouped access

Abstract

The method includes steps: (1) based on size of each transmission block (TB size) specified in technical standard 25.321, V5.10.0 for 3GPP, through emulation determines corresponding SNR under Gaussian channel; (2) using midamble part and DwPTS in time slot taken up by TS0, HS - DSCH of current TTI estimates SNRs at theses time slots; (3) calculating slopes of SNR change on these time slots and weighted mean of slopes in order to obtain mean SNR of current TTI; (4) based on obtained slopes, the invention predicts SNR of next frame, then, using coincidence relation between SNR and size of transmission block obtains modulating and encoding scheme will be adopted by next TTI.

Description

technical field [0001] The invention relates to a link adaptive method based on SINR prediction in high-speed downlink packet access, in particular to a method suitable for 1.28Mcps TDD (Time Division Duplex, time division duplex) HSDPA (High Speed ​​Downlink Packet Access, Link Adaptation Scheme Based on SINR Prediction in High Speed ​​Downlink Packet Access) System. Background technique [0002] Starting from the R5 version of the 3GPP (3rd Generation Partnership Project, three-generation partnership) technical standard, HSDPA has been formally standardized as an enhancement technology of the 3G mobile communication system. 1.28Mcps TDD HSDPA mainly adopts AMC (Adaptive Modulation and Coding, adaptive modulation and coding), FCS (Fast Cell Selection, fast cell selection), multi-antenna transmission, short TTI (Transmission Time Interval, transmission time interval) (5ms) and HARQ (Hybrid Automatic Repeat Request, Hybrid Automatic Repeat Request) and other novel technologi...

AI Technical Summary

Problems solved by technology

The strength of the correlation is related to the Doppler frequency shift of the system, that is to say, when the vehicle speed changes from slow to fast (corresponding to a relatively large Doppler frequency shift), the correlation between channel sampling points with the same sampling interval From strong to weak, it is obvious that when the speed of the vehicle is very fast, the accuracy of channel prediction becomes difficult to guarantee, so all prediction methods can only meet the performance requirements of the system within a certain speed range

The current channel prediction schemes all have the disadvantages of relatively high complexity or the physical channel model adopted is out of reality

For example the literature "Prediction of Mobile Radio Channels", T. Ekman, Licentiate thesis, Department of Signals and Systems, Uppsala University of Technology, Dec. 2000. and "Prediction of Fast Fading Parameters by Resolving the Interference Pattern," T. Eycoez, A. Duel-Hallen, H. Hallen, Signals, Systems & Computers, Conference Record of the Thirty-First Asilomar Conference on, Volume: 1, 2-5 Nov 1997 Page(s): 167-171 for each of the tapped delay channel models The channel coefficient is simulated by AR (Autoregressive, autoregressive) or ARMA (Autoregressive-moving Average, autoregressive moving average) model, and approximated by Wiener filter or Kalman filter, and finally passed through the low-pass band limited to Doppler frequency Filter smoothing, this method needs to estimate the first-order and second-order statistics of the channel tap coefficients, and each tap coefficient must be estimated, the computational complexity is very high, especially for the TDD system, because the insertion The way of the pilot frequency, which caused great difficulty to the final convergence of Wiener filter or Kalman filter

Images