Abstract:
A communication system (10, 68) includes a plurality of different, spectrall y separated air-interfaces providing different services from co-located base sites (70-76). One of these air-interfaces, which may be CDMA, operates a universal frequency-re-use pattern across multiple cells (80-88, 90), wherea s other air-interfaces, such as GSM, have carrier frequencies that a cell re-u se pattern. A subscriber unit (12-16) within the system (10-68) monitors an interference environment and path loss of at least some of the various different services to infer propagation conditions that are likely to be experienced within a spread spectrum service supported by the universal frequency re-use pattern. Armed with an assessment of fade (82-86) condition within the system as a whole, implied by time and path loss from broadcast signals from different services, the subscriber unit can regulate and contro l its power transmission. Spread spectrum communication to a distant base station can be safe in the knowledge that high power transmissions from the subscriber are subject to deep fade when viewed by near-in base sites. Near- far problems associated with high power transmissions to near-in base sites can therefore be mitigated based on a level of confidence that is found in t he fade condition determined bypath loss in services ancillary to the spread spectrum service.
Abstract:
Overloaded base stations (2,3,4) in a cellular communications network are moved down in the active sets of mobile terminals (1) by applying an offset to the received pilot power estimates. An overloaded base station will transmit a high offset value to a terminal (1), causing it to be moved down in the active set, thereby discouraging the terminal from requesting access or handover to such base station. The invention has the advantage over known cell breathing techniques in that it does not reduce cell coverage.
Abstract:
A communication system (10, 68) includes a plurality of different, spectrally separated air-interfaces providing different services from co-located base sites (70-76). One of these air-interfaces, which may be CDMA, operates a universal frequency-re-use pattern across multiple cells (80-88, 90), whereas other air-interfaces, such as GSM, have carrier frequencies that a cell re-use pattern. A subscriber unit (12-16) within the system (10-68) monitors an interference environment and path loss of at least some of the various different services to infer propagation conditions that are likely to be experienced within a spread spectrum service supported by the universal frequency re-use pattern. Armed with an assessment of fade (82-86) condition within the system as a whole, implied by time and path loss from broadcast signals from different services, the subscriber unit can regulate and control its power transmission. Spread spectrum communication to a distant base station can be safe in the knowledge that high power transmissions from the subscriber are subject to deep fade when viewed by near-in base sites. Near-far problems associated with high power transmissions to near-in base sites can therefore be mitigated based on a level of confidence that is found in the fade condition determined by path loss in services ancillary to the spread spectrum service.
Abstract:
An adaptive antenna array (14) includes a multiplicity of antenna elements (12a-12k, 48a-48k) responsive to uplink communications (16a-16k) and arranged to support directional-orientated downlink communication to subscriber units (18). The adaptive antenna array (14) is operationally responsive to a signal processor (28) that co-operates with direction of arrival estimation logic (36) to assess an angle of arrival of uplink communications incident to the array. To avoid inter-cell interference, especially during early stages of a call, the signal processor operates to ensure that a wide area downlink beam (108) is provided for a downlink path to an addressed subscriber unit. With time and/or with reported (68,84) downlink quality of service (QoS) metrics, the signal processor (28) regulates (74, 92, 96) a width of the downlink beam by altering the number of antenna elements used to support the downlink beam, thereby altering the downlink beam aperture. Generally, with time, more antenna elements (92) are used and so the beam is narrowed, although in-call fluctuations in downlink quality of service are dynamically addressed.
Abstract:
An adaptive antenna array (14) includes a multiplicity of antenna elements (12a-12k, 48a-48k) responsive to uplink communications (16a-16k) and arrange d to support directional-orientated downlink communication to subscriber units (18). The adaptive antenna array (14) is operationally responsive to a signa l processor (28) that co-operates with direction of arrival estimation logic (36) to assess an angle of arrival of uplink communications incident to the array. To avoid inter-cell interference, especially during early stages of a call, the signal processor operates to ensure that a wide area downlink beam (108) is provided for a downlink path to an addressed subscriber unit. With time and/or with reported (68,84) downlink quality of service (QoS) metrics, the signal processor (28) regulates (74, 92, 96) a width of the downlink bea m by altering the number of antenna elements used to support the downlink beam , thereby altering the downlink beam aperture. Generally, with time, more antenna elements (92) are used and so the beam is narrowed, although in-call fluctuations in downlink quality of service are dynamically addressed.
Abstract:
An adaptive antenna array (14) includes a multiplicity of antenna elements (12a-12k, 48a-48k) responsive to uplink communications (16a-16k) and arranged to support directional-orientated downlink communication to subscriber units (18). The adaptive antenna array (14) is operationally responsive to a signal processor (28) that co-operates with direction of arrival estimation logic (36) to assess an angle of arrival of uplink communications incident to the array. To avoid inter-cell interference, especially during early stages of a call, the signal processor operates to ensure that a wide area downlink beam (108) is provided for a downlink path to an addressed subscriber unit. With time and/or with reported (68, 84) downlink quality of service (QoS) metrics, the signal processor (28) regulates (74, 92, 96) a width of the downlink beam by altering the number of antenna elements used to support the downlink beam, thereby altering the downlink beam aperture. Generally, with time, more antenna elements (92) are used and so the beam is narrowed, although in-call fluctuations in downlink quality of service are dynamically addressed by the signal processor (28) by either narrowing or broadening the width of the downlink beam by respectively switching antenna elements (12a-12k, 48a-48k) into (92) or out (96) of the adaptive antenna array (14), as shown in FIGs. 3a and 3b.