Abstract: A cellular communication system includes a plurality of base stations (20), each of which assigns all frequency division multiplex, forward link carriers (32) to either a high-power set (42) of carriers (32) or a low-power set (44) of carriers (32) to improve system capacity and reduce boundary interference in a K=1 frequency reuse plan. The low-power set (44) has fewer members than the high-power set (42). The carriers (32) are simultaneously transmitted, preferably from an omnidirectional antenna (26). Access terminals (76) are configured to select carriers (32) from low-power set (44) for the receipt of data from base stations (20) when such carriers (32) from low-power set (44) provide an acceptable data rate, even though other carriers (32) may have higher SINR.

Abstract: A carrier tracking circuit includes a first phase adjustment circuit coupled to an input of a delay element and a second phase adjustment circuit coupled to an output of the delay element. A phase correction circuit is coupled to output of the delay element is operable to generate a phase adjustment value based upon a data symbol output from the delay element. The phase correction circuit includes a double phase correction circuit to prevent double application of the same phase adjustment value to a symbol by both the first and second phase adjustment circuits. The carrier tracking circuit may be used in OFDM communications systems with each data symbol being an OFDM symbol and with the delay element being an FFT. The carrier tracker circuit also may include a feed forward circuit for correcting the phase error of a given data symbol using a phase error generated from that symbol.

Abstract: A communication system (20) includes a hub radio (22) that wirelessly communicates with any number of user radios (24). The hub radio (22) monitors signal quality measurements compiled from the communication signals (30?) transmitted from the various user radios (24) and based upon baseband quadrature constellation point error to estimate out-of-band signal energy for the communication signals (30?). The hub radio (22) formulates commands based upon these measurements that instruct the user radios (24) how to adjust their power amplifier linearizers (66) so that their power amplifiers (74) become better linearized to minimize spectral regrowth and insure compliance with a spectral template.

Abstract: A constrained-envelope digital communications transmitter (10) places constraints on the envelope of a spectrally constrained, digitally modulated communication signal (42) to lower peak-to-average power ratio without allowing significant spectral regrowth. A communication signal (14,42) is applied to a plurality of cascade-coupled constrained-envelope generators (50). Each constrained-envelope generator (50) detects overpeak events (52) and configures corrective impulses (54) for the overpeak events (52). The corrective impulses (54) are filtered into shaped pulses (88) that exhibit a constrained spectrum and combine with the communication signal (14, 42) to reduce an unwanted signal peak. Trailing portions (92) of the shaped pulses (88) are fed-back and combined with the communication signal (14,42) so that future overpeak events (52) are identified after compensation is made for the influence of the trailing portions (92) of any recently past shaped pulses (88) on the communication signal (14,42).

Abstract: A radar detector (10) includes a first period detector (76, 122), a second period detector (96, 120) and a third period detector (86, 124) within a multi-period periodicity validator 38. The first period detector (76, 122) detects radar pulses exhibiting one-half of an expected pulse period (48), the second period detector (96, 120) detects radar pulses exhibiting the expected pulse period (48), and the third period detector (86, 124) detects radar pulses exhibiting twice the expected pulse period (48). A plurality of pulse-train records (40) can simultaneously track a plurality of possible pulse trains. A control element (84, 136, 138) accounts for missing pulses and corrects the expected pulse period when missing pulses have caused the expected pulse period to be inaccurate.

Abstract: A radar detector (10) includes a first period detector (76, 122), a second period detector (96, 120) and a third period detector (86, 124) within a multi-period periodicity validator 38. The first period detector (76, 122) detects radar pulses exhibiting one-half of an expected pulse period (48), the second period detector (96, 120) detects radar pulses exhibiting the expected pulse period (48), and the third period detector (86, 124) detects radar pulses exhibiting twice the expected pulse period (48). A plurality of pulse-train records (40) can simultaneously track a plurality of possible pulse trains. A control element (84, 136, 138) accounts for missing pulses and corrects the expected pulse period when missing pulses have caused the expected pulse period to be inaccurate.

Abstract: A constrained-envelope digital communications transmitter (10) places constraints on the envelope of a spectrally constrained, digitally modulated communication signal (42) to lower peak-to-average power ratio without allowing significant spectral regrowth. A communication signal (14,42) is applied to a plurality of cascade-coupled constrained-envelope generators (50). Each constrained-envelope generator (50) detects overpeak events (52) and configures corrective impulses (54) for the overpeak events (52). The corrective impulses (54) are filtered into shaped pulses (88) that exhibit a constrained spectrum and combine with the communication signal (14, 42) to reduce an unwanted signal peak. Trailing portions (92) of the shaped pulses (88) are fed-back and combined with the communication signal (14,42) so that future overpeak events (52) are identified after compensation is made for the influence of the trailing portions (92) of any recently past shaped pulses (88) on the communication signal (14,42).

Abstract: A communication system (20) includes a hub radio (22) that wirelessly communicates with any number of user radios (24). The hub radio (22) monitors signal quality measurements compiled from the communication signals (30′) transmitted from the various user radios (24) and based upon baseband quadrature constellation point error to estimate out-of-band signal energy for the communication signals (30′). The hub radio (22) formulates commands based upon these measurements that instruct the user radios (24) how to adjust their power amplifier linearizers (66) so that their power amplifiers (74) become better linearized to minimize spectral regrowth and insure compliance with a spectral template.

Abstract: A carrier tracking circuit includes a first phase adjustment circuit coupled to an input of a delay element and a second phase adjustment circuit coupled to an output of the delay element. A phase correction circuit is coupled to output of the delay element is operable to generate a phase adjustment value based upon a data symbol output from the delay element. The phase correction circuit includes a double phase correction circuit to prevent double application of the same phase adjustment value to a symbol by both the first and second phase adjustment circuits. The carrier tracking circuit may be used in OFDM communications systems with each data symbol being an OFDM symbol and with the delay element being an FFT. The carrier tracker circuit also may include a feed forward circuit for correcting the phase error of a given data symbol using a phase error generated from that symbol.