×

Method of adjusting the length of a data block in a time-division multiple access communication system

  • US 5,606,580 A
  • Filed: 07/19/1994
  • Issued: 02/25/1997
  • Est. Priority Date: 07/20/1993
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of adjusting the length of a data block (BD) in accordance with time-varying behavior of a communication channel, the data block being transmitted as a signal on the time-varying communication channel of a time-division multiple access (TDMA) communication system, the signal being received at a receiver, said data block (BD) comprising:

  • a training sequence (SA) including a reference sequence (SR) of length P; and

    a data sequence (D) of length ns containing data symbols having a symbol interval (Ts), said communication channel having an impulse response of finite length K, the method comprising the steps of;

    estimating the impulse response of the communication channel from received symbols of the reference sequence (SR);

    estimating a signal-to-noise ratio from the channel impulse response;

    estimating a maximum doppler shift of the signal at the receiver;

    calculating, from the signal-to-noise ratio, the doppler shift, the length K of the impulse response, the length P of the reference sequence (SR) and the symbol interval (Ts), lower and upper limit functions of normalized estimate mean squared error (Emin (ns), Emax (ns)) as a function of the length ns of the data sequence (D);

    determining a range for an optimal length of the data sequence (D) from the upper and lower limit functions and from a predetermined range of mean squared error which is acceptable in the communication system; and

    adjusting the length ns of the data sequence (D) to a length nopt which lies within said range for an optimal length of the data sequence.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×