Abstract: The invention is a novel slot structure and method of transmitting data at a controllable power level. The slot comprises a header, a DATA field adjacent the header and a ramp interval adjacent the DATA field. The method consists of transmitting the entire slot at a sufficiently high power when the DATA field is occupied by data traffic or control information but to lower the power during transmission of the DATA field when the slot is a null slot. In the latter case, a gradual decrease of the transmitted power is effected during the first few symbols of the DATA field, whereas the power is brought back to a higher level during the ramp interval. The new power level may be higher or lower than the initial power level, depending on the destination mobile unit associated with the following slot.

Abstract: A method for phase encoding DPSK and N-PSK which maintains phase continuity and which does not require any reference symbols when using N-PSK. A sequence of known DPSK phases are encoded with respect to an initial phase. The N-PSK phases are then all offset by this same initial phase. The known DPSK phases can be used at a receiver to determine a sum consisting of the initial phase and any further phase shift introduced by the channel, and this sum is used to decode the unknown N-PSK phases. The method is more generally applicable to any case where a switch between a phase encoding method which requires an absolute phase reference and a phase encoding method which does not have an absolute phase reference is to be implemented on a single carrier or channel.

Abstract: The timing of an access burst received in a base station of a wireless communications system is determined by detecting one or more zero bit fields, constituting predetermined sequences of identical consecutive symbols in the access burst. For each possible timing of the access burst, whether a predetermined sequence is present in the respective position in the access burst is detected by predicting a sample of the received signal in the current symbol period from a sample of the received signal in the preceding symbol period assuming identity of symbols in the current and preceding symbol periods, producing a squared distance between predicted and received samples for the current symbol period, producing a threshold in dependence upon a power of the received signal for the preceding symbol period to accommodate fading, and comparing the squared distance with the threshold, continuing for successive current symbol periods until the end of the sequence or until the respective threshold is exceeded.

Abstract: The invention is a novel method enabling a base station receiver to quickly and accurately validate a coded digital verification color code (CDVCC) vector received from a mobile station against a locally stored CDVCC vector identifying the cell to which it belongs. At the base station receiver, the received signal is sampled at twice the transmitted symbol rate, producing complex-valued samples of the received symbol envelope. These contain the received CDVCC vector and a known SYNC vector, and are assumed to have undergone dispersion characterized by several dispersion coefficients. The SYNC vector is detected with relative ease, allowing the establishment of a reference sample time. This is followed by the receiver determining a plurality of possible starting times (or “shifts”) for the CDVCC vector relative to the reference sample time.

Abstract: This detector is for demodulating a received signal having been previously encoded by a trellis coded modulator and for producing an information data signal with reduced intersymbol interference. The detector comprises a predictor, a delay line, a feedforward filter, an adder, a subtracter, an updater and a trellis coded modulation estimator. The trellis coded modulation estimator has a feedback filter which is adjusted with respect to the feedforward filter to form a decision-feedback equalizer. Moreover, the delay line has a predetermined length which is adjusted according to an order of the feedforward filter and a depth of the trellis coded modulation estimator to achieve a zero relative delay between an output of the feedforward filter and outputs of the trellis coded modulation estimator.