Abstract: A signal strength estimation circuit for a code division multiple access system comprises a channel compensator, a demodulator, an extractor and an average circuit. The channel compensator compensates different channel effect upon a received signal and outputs first and second compensated signals wherein the received signal comprises a first signal and a second signal. The demodulator electrically connected to the channel compensator demodulates the first and second compensated signals and outputs first and second demodulated signals wherein the demodulator demodulates the first and second compensated signals by corresponding 4 bits pilot patterns when each of the first and second compensated signals only has 2 pilot bits in a slot and the second signal is obtained by space time transmit diversity encoding the first signal. The extractor coupled to the demodulator respectively extracts first and second pilot signals from the first and second demodulated signals.

Abstract: An apparatus for determining multipath correlations among a search range of input data, and a method thereof. The multipath searcher comprises a pseudo noise (PN) code generator, a correlator, and a data combiner. The PN code generator generates a first PN code corresponding to a first multipath component of the input data, postpones a first period based on the search range, then generates a second PN code corresponding to a second multipath component of the input data. The correlator is coupled to the PN code generator, and correlates the input data with the first PN code and the second PN code to produce a first correlation and a second correlation. The data combiner is coupled to the correlator, receives the first and the second correlations to determine a primary multipath component with a higher correlation thereto.

Abstract: An apparatus, spread spectrum receiver, and method of controlling a circular buffer, comprising a circular buffer and a controller coupled thereto. The circular buffer receives first data at a first data rate and second data at a second data rate. The controller determines a first range in the circular buffer based on the first data rate and a first time difference between the first write and first read speed, accesses the first data in the first range, estimates a second range in the circular buffer based on the second data rate and a second time difference between the first write and first read speed, and accesses the second data in the second range, where the second range is larger than and partially covered by the first range.

Abstract: A mechanism is disclosed for imposing a delay on a variable rate information stream. A stream of information sets is received, where the stream has a variable information rate that can change from time period to time period. In a first time period, information sets are stored into a first buffer. In a second time period, information sets are stored into a second buffer. Because of the variable information rate, the number of information sets stored into the first and second buffers may differ. After a delay period has elapsed since the beginning of the first time period, the information sets in the first buffer are outputted. After a delay period has elapsed since the beginning of the second time period, the information sets in the second buffer are outputted. In this manner, a consistent delay is imposed on the information sets regardless of the information rate of the stream.

Abstract: A signal strength estimation circuit for a code division multiple access system comprises a channel compensator, a demodulator, an extractor and an average circuit. The channel compensator compensates different channel effect upon a received signal and outputs first and second compensated signals wherein the received signal comprises a first signal and a second signal. The demodulator electrically connected to the channel compensator demodulates the first and second compensated signals and outputs first and second demodulated signals wherein the demodulator demodulates the first and second compensated signals by corresponding 4 bits pilot patterns when each of the first and second compensated signals only has 2 pilot bits in a slot and the second signal is obtained by space time transmit diversity encoding the first signal. The extractor coupled to the demodulator respectively extracts first and second pilot signals from the first and second demodulated signals.

Abstract: An apparatus for determining multipath correlations among a search range of input data, and a method thereof. The multipath searcher comprises a pseudo noise (PN) code generator, a correlator, and a data combiner. The PN code generator generates a first PN code corresponding to a first multipath component of the input data, postpones a first period based on the search range, then generates a second PN code corresponding to a second multipath component of the input data. The correlator is coupled to the PN code generator, and correlates the input data with the first PN code and the second PN code to produce a first correlation and a second correlation. The data combiner is coupled to the correlator, receives the first and the second correlations to determine a primary multipath component with a higher correlation thereto.

Abstract: A fast, low-complexity detection scheme for determining the delays and gains of different propagation paths (i.e., multi-paths) of a received WCDMA signal. The method utilizes a continuous pilot channel that is scrambled by an known pseudo-random sequence. The received signal is provided to a multi-path searcher that passes the received signal through a matched filter with a specified number of taps. The matched filter correlates the received signal with the pilot channel. The multi-path gain and delay detection is then performed, and the delays and gains are reported for use in the WCDMA system.

Abstract: A mechanism is disclosed for imposing a delay on a variable rate information stream. A stream of information sets is received, where the stream has a variable information rate that can change from time period to time period. In a first time period, information sets are stored into a first buffer. In a second time period, information sets are stored into a second buffer. Because of the variable information rate, the number of information sets stored into the first and second buffers may differ. After a delay period has elapsed since the beginning of the first time period, the information sets in the first buffer are outputted. After a delay period has elapsed since the beginning of the second time period, the information sets in the second buffer are outputted. In this manner, a consistent delay is imposed on the information sets regardless of the information rate of the stream.

Abstract: An apparatus, spread spectrum receiver, and method of controlling a circular buffer, comprising a circular buffer and a controller coupled thereto. The circular buffer receives first data at a first data rate and second data at a second data rate. The controller determines a first range in the circular buffer based on the first data rate and a first time difference between the first write and first read speed, accesses the first data in the first range, estimates a second range in the circular buffer based on the second data rate and a second time difference between the first write and first read speed, and accesses the second data in the second range, where the second range is larger than and partially covered by the first range.

Abstract: A decision feedback loop for a receiver for channel estimation and de-rotation of complex input symbols derived from a sampled information signal received via a channel which contains data organized into successive time slots, is configured to retrain and reinitialize the loop during each slot in order to mitigate slot to slot propagation of the estimation error.