Abstract: Disclosed is a telecommunication system that is both highly cost effective for small scale applications (for example, those having less than 80 lines), yet field upgrade-expandable to applications having a significant number of additional lines (for example, 30,000 lines). An integrated voice/data telecommunication system is utilized that is flexible enough to handle low bandwidth (for example 64 kbps mu-law) speech as well as high bandwidth multimedia data switching. The system may be configured as a low cost, standalone PACS system for "village telephony" or "PACS-on-POTS" applications, as an alternative to requirements for PACS infrastructure when appropriate wireless network facilities are unavailable.

Abstract: A bimodal portable telephone provides cellular service and improved cordless service in a common handset. Operation of the bimodal portable telephone in a cellular telephone system provides telephone service over a wide geographical area of coverage through operation with multiple cellular bases and in a cordless telephone system provides telephone service over a localized geographical area of coverage through operation with an associated cordless base. The cordless service provides improved performance over convention cordless telephone service by advantageously employing a frequency hopping spread spectrum modulation technique for communications between the portable telephone and the cordless base unit. This improved performance achieves increased operating range of the cordless telephone system.

Abstract: A cordless telephone arranged for operation in a frequency hopping system conserves battery power in a handset unit when this unit is located remote from an associated base unit and in a standby state. While in this standby state, the handset unit resides in a low power monitoring mode and monitors a channel pseudo-randomly selected from a plurality of available channels in the frequency hopping band for receipt of an initialization signal from the associated base unit. The base unit similarly monitors this selected one of the channels for receipt of this initialization signal from the handset unit. Should ongoing communications between the base unit and the handset unit be inadvertently interrupted, the cordless telephone quickly re-establishes communications in the frequency hopping system through an initialization process executed by both the handset unit and the base unit.

Abstract: A cordless telephone arranged for operation in a frequency hopping system automatically modifies a frequency hopping sequence in the presence of interference detected on its in-use communication channels. Substitute alternative communication channels are identified and then substituted for those communication channels experiencing the interference without disruption of communications between a handset unit in the cordless telephone and its associated base unit.

Abstract: A technique for reducing the average fade duration of signals in a radio system by simulating motion of a plurality of transmitting antennas is disclosed. This simulation is accomplished by slowly and continuously varying a characteristic of the modulated carrier signal supplied to the antennas. The altered characteristic can either be the power of the modulated carrier signal supplied to each of the antennas or the phase between modulated carrier signals coupled to the antennas. This technique can also be applied at a receiver to reduce the average fade duration of signals arriving thereat by simulating motion of a plurality of receiving antennas.

Abstract: In a single sideband radio receiver utilizing a limited, pilot-controlled, gain correction arrangement (38) to compensate for radio channel fading, a signal (RECT CAP) representing receiver audio output level is utilized (97) during intersyllabic quiet intervals to increase the limiting threshold on the gain correction signal to suppress noise and interference.

Abstract: In a cellular mobile radiotelephone system in which the service regions of a channel reuse cluster of N.sub.C cells are characterized by a channel reuse distance D.sub.C, the regions are assigned transceiver algorithm implementations according to an implementation reuse cell cluster size of N.sub.A cells which are characterized by a reuse distance D.sub.A, the combined reuse distance D.sub.CO for reuse of a given combination of channel set and implementation is greater than the distance D.sub.C. Additional illustrative implementation arrangements are shown.

Abstract: The numbers of cycles in a received signal including Doppler frequency spread are counted (36) modulo a base value much smaller than the number of cycles in such received signal during a predetermined measuring interval for thereby averaging out the effects of such frequency spread in the counter output. That output is utilized to control the frequency of a local oscillator (26) to lock it to the frequency of the received signals. The actual duration of the measuring interval is set (39) in accordance with a signal provided from the oscillator. Also shown are circuits (45, 23) for causing the oscillator initially to lock to a radio system master reference frequency and thereafter to lock, in a narrow frequency band, to a pilot frequency of a specified information channel.

Abstract: Effects of multipath fading and Doppler frequency spread in a single sideband radio communication system are largely overcome by separating (17) from a received signal spectrum, a pilot frequency component including those effects and using that component to accomplish both phase (36) and gain (38) corrections on an information-containing frequency component. Signals essentially free of those effects are provided (10) for controlling necessary frequency translations in the receiver. One illustrative embodiment (FIG. 4) is conveniently arranged for facilitating diversity signal combining.